47 Replies Latest reply on Aug 27, 2020 9:15 PM by dougw

    How can I deal with resistors when I'm colorblind?


      Hey guys, Mike Wiltrout here.  I believe many of you may know my father, John Wiltrout.


      This really is not much of an introduction post, but it is my first on E-14.  It is picture laden so I apologize for that ahead of time.  I did, however, feel like it would be an interesting topic that some of you might be able to help me with, so here goes!


      In my early childhood, I recall wanting to be a fireman.  One day, my mother took me in to the clinic for a school physical.  It was then that the doctor showed me a series of images with different color dots on them to determine if I was colorblind.  Supposedly somewhere in the mix of dots on each image was supposed to be a number that I was to recite when I could make it out.  Unfortunately for me I could make very few of them out.  Below is an example of just such a chart and on that chart below I can really only make out the '12' in the upper right corner.  It was then that the doctor began telling me about all of the careers that I would never be able to pursue.  Included in that list was fireman.  When I asked the doctor why I would not be able to be a fireman, he told me that firemen need to be able to see colors to be able to tell how hot a flame was.  So I left the doctor's office that day a little bit sad and discouraged.

      Color blind chart.jpg

      My father, being the troubleshooter that he is, set out to try and help me with my colorblind condition.  He picked up color swatches in hopes that I might be able to "re-learn" the colors or at least be able to use the color swatches to compare against colors I wanted to know.  Turns out it just doesn't work that way.  The problem comes with being unable to differentiate.  Red can look like orange, orange can look like yellow, yellow can look like green, green can look like blue, and so on.  ORANGE means STOP and WHITE means GO!  As a teen, I was interested in flying and wanted to get into the Air Force Academy, but pilots need to be able to see colors so they can tell if a plane is coming at them or flying away from them using colors on the wing and tail.  I then considered the National Guard, where I was told that I could not be an engineer and that the ONLY military career paths that were open to me were about few different ones: a chaplain, a draftsman, or an infantryman.  They wouldn't even let me be a cook because I cannot tell if meat is raw or cooked.  Anyhow, you get the idea, being color blind can be a challenge.  My wife finally made me get rid of my favorite blue office chair, because she could no longer stand the "hideous purple thing."


      So, here is and has been my dilemma.  How do I differentiate and identify the various color coded resistors?


      My solutions so far consist of the following:


      • GET A BUDDY TO HELP ME - Preferably a buddy who is also not colorblind, but while a buddy might be able to help me sort a new collection of resistors into bins, he isn't going to be attached to my hip when I need a resistor identified on a project that I'm working on at 3AM.IMG_2412.JPG
      • MEASURE THE RESISTOR USING A MULTIMETER - This may work to identify a resistor outside of a circuit, but it also does not take into account any tolerances of the resistor, which I also cannot discern.  I do not want to de-solder a leg on each resistor I need to measure on a PCB, either.
      • LABEL THE RESISTORS - This will work if I buy resistors that are in label pre-packaged bags and I am able to label them right away.  I probably would look to label them according to either European or SMT standards in order to keep the labels as small as possible.  This method takes a considerable amount if time, and I will probably only use it for prototyping.
      • PREMARKED RESISTORS - Some resistors like SMT resistors have their values printed on them.  These I can figure out.
      • VISUAL COMPUTER AIDED ANALYSIS - Another idea that I had was to use either a camera, or a USB microscope to "scan" the resistor.  The image could then be dropped into a computer program that would orient the resistor and scan the color bands displaying a value in Ohms and providing me the tolerance.  I have no experience with any program that can automatic manipulation and color matching, so I'm stuck there.
      • FIX MYSELF? - The last idea would be to somehow fix myself with some type of contacts, glasses, or other medical method.  (Again, not my field of expertise.)


      The problem is not limited to resistors, either.  I'm thinking a career in bomb disposal sounds pretty interesting, "Should I cut the RED wire or the BLUE wire?"


      So lets hear some suggestions!  GO!

        • Re: How can I deal with resistors when I'm colorblind?

          Hello Mike


          Firstly welcome to the Element 14 community and congratulations on an entertaining first post!


          As your father will no doubt have advised you, we are a helpful bunch here, so feel free to snap a photo of a resistor and post it here anytime.

          The best long-term approach to your situation IMHO would be to explore the visual computer aided analysis you mentioned. Not only does it sound like a really cool idea, it would no doubt help others.


          Luckily, somebody has taken a very similar approach already, you can read more about it here: http://armageddon421.de/?p=279

          1 of 1 people found this helpful
          • Re: How can I deal with resistors when I'm colorblind?

            Hi Mike,

            You know I never thought about this problem before and I can see how difficult it would be to use the color codes if you are color blind (Virtually impossible) I remember Google glasses was an app on the droid phone that would identify items by taking a picture of it. I am not sure if it is still in use, but may offer a solution to your problem, not to mention easily more portable that a tablet, or you could take a mobile picture and text it to your buddy. sorry I can't be more helpful. Great presentation and welcome to the community.

              • Re: How can I deal with resistors when I'm colorblind?

                Google glass would be AWESOME and very handy.  Asking a colorblind man to see colors is like asking a blind man to see -- It is extremely difficult.

                I was striving for perfection in my first post, but I noticed that I have fallen short:  Bad english, typos, and pictures not landing where they are supposed to. I'll be more careful and try harder next time.  Where is that EDIT button when you need it.

              • Re: How can I deal with resistors when I'm colorblind?


                You don't need to be colour blind to have trouble.

                Us older ones can tell you that the smaller they are, the worse it is.


                However having said that some of the cheap resistors from Asian sources have colours that are 'close' to the proper, but sometimes not.

                We have a Xmas Tree project for pupils and appart from a process of elimination, the meter often comes out.


                I'm wondering if filters in front of the resistor and the use of UV/IR light might make some colours there and others not.

                As for stocks, I can only suggest stick to the e27?? range and use the plastic bags the banks give out for change.



                You're right they label them, but only the larger size ... I have some grains of sand that are apparently reistors.


                Nice topic, welcome to the forum.



                • Re: How can I deal with resistors when I'm colorblind?

                  Good Post Mike, BTW if you know the % tolerance a range of resistors in your pot or dustbin are then measuring them does tell you what they should be as they choose the range values to allow you to make up any value you want to with in that 1-5% or what ever. Any way even if they are at their full tolerance they should be closer to the value they should be than to any other value in the series.


                  Anyway the resistance you measure is the resistance you have so maybe that's more important than the stripes ...not that most designs are that ultimately fussy any road 


                  Keep the posts up!

                    • Re: How can I deal with resistors when I'm colorblind?

                      I agree completely John, what you measure is what you actually have for resistance at that time and temperature no matter what color bands are on a resistor, but it still doesn't help me when the resistor is in a circuit and cannot be easily isolated. 

                        • Re: How can I deal with resistors when I'm colorblind?

                          Yeah you are right... Although if it's an SMD device you'd be luck to even see it and also I think the App would have difficulty identifying the  component you were on about if faced with a board full. Also I doubt it could do a good enough Macro unassisted.


                          Maybe one of those inspection  cams at £30-250 would be good along with an App.. Take a pic then ask it "Wot's That?"

                          • Re: How can I deal with resistors when I'm colorblind?

                            I had picked up a 5MP 50X-500X 8 LED USB Digital mircroscope from Amazon for less than $30.  It had been previously mentioned, that a camera on a phone may not have the macro capabilities to zoom in and view a specific resistor on a PCB.  I used the USB microscope to capture an image of a resistor, thinking that maybe if it was blown up and close to a color pallet that it might help.  To illustrate just how messed up my interpretation of the colors are, I'm going to tell you what I see.  I took the screen images with my phone instead of using a screen capture so I apologize for that ahead of time.

                            In this image, I see colors/shades that I believe to be: ORANGE BLUE GREEN GOLD.

                            The bad part about this is that it is a 560 Ohm resistor, so the colors should really be GREEN BLUE BROWN GOLD.

                            Hmm, 2 colors out of 4.  50% isn't half bad, is it?

                            Having a color pallet below the image does not seem to help me.  If I could possibly use a software color sample tool that could grab the color from the picture and tell me what it was that would probably work.


                            Even if the USB camera does not, in the end, get used for my CB issues, I think it will still be useful for those old man issues, so that is good. (iPhone left & microscope right)


                              • Re: How can I deal with resistors when I'm colorblind?

                                Using the USB microscope take a picture of the part and then run it through an image viewing program such as Irfanview that will let you manipulate the colors. For example, sequentially adjust the red, blue and green levels and note the changes. With some practice you could be able to associate the relative changes with the actual color.

                                • Re: How can I deal with resistors when I'm colorblind?

                                  Would it help to have an app where you have a cursor that numerically indicates the RGB color values under the cursor?

                                  Actually the Hue value is probably enough - so a cursor that has a little hue box attached would allow you to move the cursor across a resistor and see the hue values of each stripe as the cursor crosses it. Better yet it could indicate the color in text form - less mental conversion, but also less accurate.

                                  Or would a rainbow spectrum plot be better - see where the cross hairs are in the color palette as below...

                                  Perhaps a cursor mapped on a CIE color chart would be better?

                                  You can manually determine the color constituents using IrfanView by using the color picker tool and clicking on the color palette as shown here - I clicked on the green band using the color picker tool, then the picked color block in the lower right corner of the Paint Tools pop-up, then the Define Custom Colors button:


                                    • Re: How can I deal with resistors when I'm colorblind?

                                      I was going to comment on illumination but to be honest most of the resistors you get now have such crap paint on them it's not so obvious what on earth they are !

                                      Reds=Browns or even Oranges

                                      Conversely for lighting you have only a certain number of combinations to  a given Exx Range so you can give a set of them or ask for the lighting to be adjusted. The tolerance Bands have even fewer combinations so really you should be able to tell if your lighting is all to pot.

                                        • Re: How can I deal with resistors when I'm colorblind?


                                          Lighting is the whole key to this, and unfortunately cheap poor quality cameras are not a suitable answer.

                                          Your 50-500X Microscope might be optically increasing the size, but if it's not optically increasing the size, then all its's doing is reducing the resolution. (as we see with the IC)


                                          Many of the smaller digital camera have an outlet that should be able to used for live feed to software, and some have optical zooms.


                                          You need an even light source to properly illuminate the subject, rather than a high powered light source that throws a lot of light on the foreground, while the background is dark.

                                          Using a 'Grey Card' as the background ensures you can adjust the lighting level and camera to ensure you are rendering red/brown as red/brown.



                                          Putting aside the resistors on a pcb for a minute ...

                                          If you had a number of sample resistor images that you could place side by side, would you be able to see they are the same/different.?

                                          Both would be similar sized as per your first image.



                                          I'm not an expert but I see you have the Green Brown colour blindness, which means certain colurs are a problem, but others are correct.

                                          Identifying this means different light colurs and a filter may offer a solution.




                                          I once knew a farmer who had the same colurs issue... when he looked at his lush green paddocks and they were brown ...

                                        • Re: How can I deal with resistors when I'm colorblind?

                                          You and Chuck are right, I could use another piece of software like IrfanView (A program that I know and love)  I could capture the image with the scope, either save the image or do a Irfanview screen capture, color pick from the image for each color, getting the RGB values, and then use those to somewhat approximate using either the ROYGBIV image cursor layout or some use of the predominant values.  However, I do not want it to be a 5 minute process to determine a single resistor's color either.  It needs to be fast and it needs to be accurate, otherwise I'm not going to want to do it, or I'm going to put the wrong value resistor into a project and blow stuff up.  Much more like the iphone program that you located Douglas.  I want to locate something like that.

                                    • Re: How can I deal with resistors when I'm colorblind?

                                      This is a good find Doug...


                                      It really looks well done, I like that colour jog wheel so you can change the value if you want !

                                      • Re: How can I deal with resistors when I'm colorblind?

                                        Now if there is a version that is available in the US and works with iOS 8+.  That being said, we are definitely moving in the right direction.  Thanks Douglas!


                                        I'm going to have to try and contact the author and see if any progress has been made.

                                        • Re: How can I deal with resistors when I'm colorblind?



                                          Even though I still have not had any success finding a working application, I wanted to again thank you for finding a solution that was directly in line with what I was looking for.  I contacted Rich, the creator of the resistor app for the iphone that you were able to locate and he got back to me finally and had this to say,


                                          "Hi Mike -


                                          Can't say that there have been any developments (or any immenent plans to update the app). 

                                          Part of this is that I've moved to Android for my own use - so I haven't been spending much time on my iOS apps.

                                          You might want to take a look at this though - might be a good solution for you:







                                          So, Anyhow, I have moved on to trying to contact the armageddon guy, who is located in Germany.  Contacting him has not yet yielded any pay dirt.  I guess I'm a crappy Java programmer because I can't seem to get Armageddon's .JAR file https://github.com.armageddon421/ResCan/releases to compile into an executable and run on my PC let alone use my USB cam.




                                          SMD is definitely an option moving forward with production.  Strips are a nice method of storage too.  However, most of my electronic project work is experimental (breadboard) or troubleshooting (repair & service of existing technology).  An application that will allow me to read the value of an existing resistor in a circuit without removing it or isolating it from a circuit for measurement is ideally what I am searching for.

                                            • Re: How can I deal with resistors when I'm colorblind?

                                              Hi Mike,

                                              I'm currently immersed in some pretty heavy projects, so I don't have much time to devote to this, but I just wrote a quick program in VB6 that will show the color of any pixel on the screen - just put the mouse pointer on a pixel and the RGB value of that pixel will be reported. It also shows a zoomed in view of the area around the mouse pointer and a swatch of the selected color around the text. you can control the zoom with a slider on the right. The screen capture software takes some time to get locked onto the activity, so the first part of the video is a pretty sketchy....

                                              This program can be used to figure out any color on screen, whether it is in a webcam window or a static image of a circuit card.

                                              I have not figured out a way to attach a program to a post like this or I would include the program, but here is a video ....

                                          • Re: How can I deal with resistors when I'm colorblind?

                                            One of the problems with taking a picture is lighting and the reflective surface of the resistor. Just like the latest debacle on the internet with the blue & black dress or white & gold dress. You can tell from the picture above that some of the color is washed out from the glare of the light used to illuminate the resistor. If the contrast is not right then the red may look brown. Perhaps we should get the industry to also print numbers on the bands so we have a verification as to what color we are actually looking at. Unfortunately that won't work so we need something that has a color corrected light source with a polarized filter for the camera lens to reduce glare and then we may get an almost accurate idea as too which colors we are looking at if they are not faded. Software to read the color bands and tolerance that can give us a numerical value with the tolerance range. I think that would aid not only colorblind people but anyone that hasn't taken the time to memorize the color codes. where to start?

                                              • Re: How can I deal with resistors when I'm colorblind?

                                                jguss43 ,


                                                Lighting and shading is an excellent point.  In the dental industry, when they go to put a false tooth in your mouth, they put the patient under daylight lighting conditions and then they pick different teeth from a shade guide.  They hold the individual shade up next to your existing teeth and move through the shade guide until they have one that most closely resembles the existing teeth.

                                                An advancement on that is that they have a device that emits a specific wavelength of light and reads the color that is reflected back to it.  It then displays a letter / number combination that coincides with the correct tooth shade to select from the guide.

                                                mcb1 , I have not taken my digital microscope apart to see if the dial that I am moving is actually moving a lens, or if it is just a potentiometer that is spinning to adjust the zoom.  I understand the differences between an optical and digital zoom, and the fact that a digitally zoomed image will decrease the dpi resolution of the image.  Some of the image issues that you see in my picture revolve around the fact that I just took a picture of the screen with my camera instead of doing an actual screen capture.  I do not think that there was a lot of pixelation at least at the resolution that I had zoomed to.


                                                My hopes with the microscope were to simply be able to capture a part in a tight location and isolate it from the surrounding parts, blow it up large enough so that I was not also fighting my eyesight as well as my color blindness.  I can control the brightness of the microscope, it is just a ring of LEDs.  I'm not sure what temperature of light that the LEDs are giving off, or if the colors reflected back are accurate or not.  I can't do much about shadows without being able to get close and illuminate the entire part, and I can't fix the fact that some resistors will be dulled and old while others may be new and shiny.


                                                The color is what the color is.  I just need to find a simple, fast, cost effective way to read them resistor's colors and Ohms.  I'd like to use the device to read the colors of wires too.  That'd be handy when I'm trying to figure out what wires are taps on a transformer, etc.  Without color recognition, I see many explosive project failures in my future. Hehe.

                                                1 of 1 people found this helpful
                                              • Re: How can I deal with resistors when I'm colorblind?

                                                OK, OK I cant believe no one has asked the obvious question especially as most of the participants of this conversation are TMs



                                                What Colour is a Minion


                                                I mean really guys, you slipping up, this has stayed on track for way too long knowing you all and I bet your all wondering


                                                Aside from that, I can totally relate to your issues, My youngest son is colour blind also and we did not realize for quite a while, he even was able to colour in pictures correctly and once we found out we had to wonder how ??


                                                He learned to read the colour printed on the crayon and it was only when the teacher deliberately took off all the covers and asked him to sort them, we finally had it confirmed


                                                It is sad that with all the technology around today this continues to be an issue for so many people but you seem to be off to a great start with E14 and this thread, we have no end of great ideas to try, some might seem a little bizarre and if your not careful, Doug may get tempted to print out some "Special" glasses for you, he is good at that


                                                Oh, Google Glass would seem a lightly candidate if it where not so expensive ?, that and some cool software to do what a few members have been suggesting


                                                I wish you luck


                                                • Re: How can I deal with resistors when I'm colorblind?

                                                  For critical applications I tend to use RN55 or RN60 resistors from Corning.  These are typically laser-engraved with a text version of the value.  They were commonly available at surplus in my neighborhood a coupla decades back and I collected them pretty systematically.  The banded versions are usually C(arbon) resistors I use for things like LED ballasts.   I can see color but don't trust my interpretation of different manufacturer's marking scheme on the fly.  So I often measure at the last.  Electro-magnetic spectrum is a continuum anyway.

                                                  • Re: How can I deal with resistors when I'm colorblind?
                                                    Jan Cumps

                                                    Have you considered switching over to smd completely, and buy components in tapes/strips?

                                                    Colors don't play a role, so that disadvantage is gone.I switched to smd in my 40's, and didn't find that move hard at all.

                                                    • Re: How can I deal with resistors when I'm colorblind?

                                                      As a color-blind individual myself, I've had to struggle with this for quite a while. I read about ReScan, on this site and others but it is PC/Android only and requires a bit of putzing to install and get going. And although the app is quite responsive and can actually read the values to you via speaker, there were limitations, clarity and other issues I wasn't all that enthused about.


                                                      Recently, though, I found a $1.99 iOS app called ResistorVision by Jera Design. It uses the iPhone's camera to accurately check and report the resistor's values. For the most part, it works quickly and well, though it, like ReScan, has some limitations:


                                                      1) ResistorVision currently only works on 4-band beige axial resistors. Blue resistors and 5-band resistors are not currently supported, nor are surface-mount resistors.

                                                      2) It needs a colorless background (preferably white or gray) to be able to detect a resistor.  A white sheet of paper or index card works fine but of course this can be a problem when trying to evaluate a resistor 'in situ'. I have resorted, once or twice, to cutting out a piece of a 3" x 5" index card and sliding it under a soldered-in resistor to provide the background the app needs. It wasn't much hassle - especially compared to unsoldering the resistor, measuring it with a MM and soldering it back in!

                                                      3) You need to position the iPhone so that the resistor almost fills a medium-sized rectangle in the center of the screen and there are, sometimes, focusing problems due to the camera focusing on the background instead of the resistor. Moving the iPhone or pointing it in another direction to cause it to refocus does the trick, though.


                                                      Overall, though, this is a very neat tool; I have had few problems with it and it is quite accurate. It's still being developed and seems to be improving as it goes. The devs ask that you email screenshots of situations where the app has problems and they use these shots to improve the program's zone and color perception. They are working on an Android version; emailing them and asking for one will undoubtedly speed up its development. Here are links to:


                                                      its very bare-bones website: ResistorVision


                                                      and its App Store page: https://itunes.apple.com/us/app/resistorvision/id839853035?mt=8



                                                      1 of 1 people found this helpful
                                                        • Re: How can I deal with resistors when I'm colorblind?

                                                          Sorry to revive a couple of year old thread, but this is the first time I've heard of an iphone app to read resistors using the phone's camera. Ironically, I discovered I was color bling the first time in a middle school electronics class, where I was the first able to answer when the teacher drew the bands in chalk and just wrote in the name of the color for each band, yet my success rate reading actual resistors was dismal. I've spent the nearly 40 years since having to dig out a meter to find the resistor I want. I've long wished for an app like the one listed, so I was super excited to find this post. Unfortunately, when I follow the above link on my iphone I get a message that "This app is currently not available in your country or region." Does anyone know if it is still being developed, or have contact info for the developer(s)?




                                                        • Re: How can I deal with resistors when I'm colorblind?

                                                          I felt compelled to register just to reply to this (slightly old) post.

                                                          I've known pretty much forever that I was Red-Green colour blind (seemingly I used to sort out my other wooden bricks as a toddler first, then differentiate these at the end).
                                                          Never been an issue to me (as I didn't want to be a fighter pilot etc).
                                                          I've done the odd bit of fiddling where I was using one or two types of resistor, and could tell them apart.
                                                          Then I got an Arduino playset, that came with a whole variety and... well I'm completely lost. First time in my life, I've actually felt I had a disability. Colour choices (and lack of patterns/labels) seem as if they were deliberately chosen to pick on me

                                                          As i'm feeling obstinate (and resistors are cheap) is there any way to buy my way out of my problem?
                                                          e.g. "clealy labelled SMT with a couple of nice stiff legs pre-applied"?
                                                          I'd have thought even for the "colour-able" having something you could just push into a breadboard with your thumb, would be preferable to what we have today - and for dev, an order of magnitude in cost wouldn't even be noticed.

                                                          If my dream doesn't exist, I do have an alternative.
                                                          Currently sketching up some tiny little 'boxes' I could 3D print. Idea would be you could press a resistor into them (and hopefully would give a nice 90-degree bend on the legs) - then glue them in, trim the legs, and you'd have a nice package you could press into the board.