Simple Color Translation Algorithms

Two weeks ago I wrote an article about Protanope Tools and how you can translate diagrams to make them more readable for colorblind people. This time we have closer look at the algorithms behind the two color translations.

To understand the how and why of the two color translations we first have look at the RGB color system. The acronym RGB encodes the colors Red, Green and Blue and is used on computer system color displays to—well— display colors.

Concerning red-green color blindness the first two channels (Red/Green) are sometimes not of great help. These two channels are encoding the color axis which gives a red-green colorblind person the most problems in distinguishing different shades. Therefore we are looking for a simple way to transform those two channels.

Red-Green Color Blindness Color Translation Algorithms

Original Color Spectrum

  • Red-Green to Blue-Yellow Translation
    Color Spectrum - Blue-Yellow

    • R -> B
    • G -> G
    • G -> R
  • Red-Green to Green-Magenta Translation
    Color Spectrum - Green-Magenta

    • R -> R
    • G -> G
    • R -> B

The two translation formulas are held very simple but not less effective. They have only one major flaw: the blue channel is completely thrown out and in both cases replaced by the red channel. So you lose a third of the information in the image, all the blue information, except that if you are red-green colorblind you gain a lot of information that was previously lost in the red and green channels.

As Peter, the owner of Protanope Tools, puts it:

I say this is a strength because the simplicity makes it easy to understand exactly what’s happening, so if you know you’re going to lose all the blue information at least that won’t take you by surprise.

Thanks Peter for the information about your simple color translation algorithms you shared with us.

Wiring as a Colorblind

It’s not always easy to live with your color blindness. One special case are all those color coded wires.

I recently came across this problem, when I tried to elongate a telephone cable. This can be a big problem if you are colorblind and have nobody around who can tell you which color is which and has to be connected to which port.

Brandon describes a similar problem while he was rewiring some cables in his house. He vent his anger in When Color Blindness Sucks.

What do we learn:

  1. Don’t work with color coded wires if you are colorblind.
  2. Because almost everything is color coded these days, stop working at all.
  3. Ask the government for support because you can’t work.
  4. Sit back and think what you could do in your spare time.
  5. Maybe some new rewiring of your cables at home?….

Dear colorblind fellows, do you have similar experiences with color codes?

The Way to Cure Color Blindness?

As for today there is no known treatment to cure color blindness but maybe in the near future there will be some possibilities to overcome color blindness and even enhance color vision overall.

Colorblind Mouse
Colorblind Mouse by Beige Alert

Researchers from the University of California and the Johns Hopkins Medical School in Baltimore showed in a series of experiments, how the color vision abilities of mice can be enhanced. Mice have naturally only dichromatic vision which can be compared to red-green color blindness. Dichromatic means, they have only two different types of color receptors in their eyes whereas humans normally have three different types which make up our color vision.

The scientists “pimped” the mice in their experiments with the missing genes for color perception which they took from humans. And those mice performed much better in the test setup as their dichromatic colleagues. This led to the assumption that the enhanced mice have a better (trichromatic) color vision.

Other researchers have also shown that they could cure color blindness in monkeys through injections of the missing color receptor genes.

What can we learn from this?

  • Color Blindness can be cured or at least it could be cured in about 6 cases of mice and monkeys so far.
  • We are on the way of the perfect human being and don’t even forget to exterminate color blindness on that way.
  • You won’t experience the cure of color blindness because this are only the first steps from a very long way.

If you are looking for a treatment of color blindness you still need to wait quite a while. And in case you can’t wait—hope dies last.

The Washington Post published an article about this research last week called Mice See New Hue With Added Gene. The original work was published in the science magazine: Emergence of Novel Color Vision in Mice Engineered to Express a Human Cone Photopigment.

Also read more about some newer scientific results on the cure of color-blind monkeys by gene therapy.

Tips when Dealing with Colorblind Customers

Earlier this month Anthony Mitchell from TechNewsWorld wrote a nice article about the usability of products and the communication of information concerning color blindness. Due to the fact that about 8% of men have a color vision deficiency this is nothing to be neglected.

The two parts of the article cover topics like good contrast colors, presenting with color blindness in your mind, color coding, and poor usability through bad color choices.

A few statements caught my attention which I would like to point out:

  • Information should never be distinguished by color only. This is a very important point which is often forgotten about. Only three different colors with high contrasts are easily distinguishable for colorblind persons. Always try to make not only color the only attribute but also use patterns, thickness of lines or borders or simply label the different parts directly if possible.
  • Colorblind people have trouble seeing light from red laser pointers. Laser pointers always give me a hard time. If they are used on presentations I have great difficulties to see the little dot. Often I concentrate so much on the red dot that I even loose track of the presentation itself.
  • Rely on black fonts and white backgrounds. It’s so simply why don’t you stick to it? Of course this is not true in all cases but for a text which should be easily readable for everybody just stick to black and white.
  • Colorblind people can find it impossible to distinguish red letters from black ones. This point is sometimes hard to believe by somebody with normal color vision. But red text doesn’t stick out at all if you are colorblind. If you use red text to show some errors for example in an input form invert the colors, make it bold, print a border or just do anything to make it more visible.
  • Distinguishing colors and naming colors are separate tasks. When it comes to naming colors I’m really bad. And with really bad I mean really really bad. I can distinguish colors but usually have big problems naming them. Color blindness makes you a color names guessing individual and not knowing one.

The article also includes a whole lot of links to better and worse examples: colors used in icons, webpages, links, and a lot more.

Maybe one or the other tip can help you to present your products more colorblind friendly or get your point across easily even with colorblind persons in your audience. You can find the whole article by following the two links below.

Think about color blindness whenever you are dealing with customers.

Did you make a Color Blindness Check on your Color Scheme?

There are many online tools which help you to choose an appropriate color scheme based on color theory. ColorJack is one of them. But not just anyone when you take color blindness into account. The creator put quite some effort into the tool to help you understand how a colorblind persons will perceive your chosen color scheme.

The most popular part of ColorJack is the Sphere application. Before I describe you all settings in detail and special adjustments concerning color blindness try it out yourself.

Besides all the settings for choosing your spectral colors according to different color theories and the possibility to set the base color spectrum you have the choice to choose between several different color vision deficiencies.

  • Dichromacy: Protanopia, Deuteranopia and Tritanopia.
  • Anomalous Trichromacy: Protanomaly, Deuteranomaly and Tritanomaly.
  • Monochromacy: Rod Monochromacy and Blue Cone Monochromacy.

The naming needs some further explanation because the labels in the Sphere tool are not well chosen. As for dichromacy which describes the circumstance, that a person has one type of color receptors missing, the correct names end with -opia and not as labeled in the tool with -opy.

The wordings Achromatopy and Achromatomaly used in the tool of ColorJack are also wrong. The correct names are either Rod Monochromacy or Achromatopsia for complete color blindness (absence of all color receptors) and on the other side, if you have only blue color receptors this is called Blue Cone Monochromacy.

Nevertheless the ColorJack Sphere application is a great tool to provide you some good information when you want to check your color scheme to work with any type of color blindness. It does not only show how your colors are perceived by somebody with a color vision deficiency but also shows the according color values. This gives you a hint on how color vision is different if you suffer from color blindness.

The perfect Wall Color

It was a very quick decision and the job was done in a couple of hours — our colored bedroom wall.

First we wanted many colored walls, then we stepped back and stayed with white walls and sometimes we move forward again and paint a wall in a fresh color.

The question is always, “which color is the right color”. For me as a colorblind this is a valuable question and also for my not colorblind wife. But we both look at it from a different perspective.

I definitely choose colors based on other visual impressions than somebody with normal color vision. So every time the same question arises: Does the chosen color fit for both.

Often this isn’t that easy and I have to agree to a compromise. Yes, most often it is me because I’m the one which can’t see the true colors and I know about it.

Now, which is the perfect wall color? I don’t know. But I have to feel ok with it and in the case of our bedroom wall it has to be a chosen color of my wife.

And which color did we choose? That’s the best part of the story: I don’t know either. It’s something between blue, violet, aubergine and pink. Blue with a touch of red. I can’t tell you and even our visitors are arguing about it which makes me feel a bit better, because I’m not the only one which has problems with matching colors and color names.

Color Translation — Readable Diagrams for the Colorblind

It can be really annoying if you find some descriptive graphics or a nice diagram and you can’t decipher it because it is color coded. Even if you are suffering from red-green color blindness — which is the most common form of color vision deficiencies — you aren’t spared to come across such diagrams.

Have a look at the following diagram of the climate classification. If you are red-green colorblind it can be a big problem to distinguish Tropical from Cold and also Dry from Temperate zones. In the first case it doesn’t really matter because the different zones are far apart form each other. The latter case is worse.

Climate Classification
Climate Classification

In such cases Protanope Tools comes in very handy. With this little online tool you can change the color spectrum and make those undistinguishable parts of color coded diagrams visible. Protanope Tools is made for red-green colorblind persons and offers two different possibilities:

  1. Shift from red-green to blue-yellow.
  2. Shift from red-green to green-magenta.

Have a look at the following two diagrams which were created with Protanope Tools based on the above image. The colors change dramatically. In both cases the climate zones Dry and Temperate are clearly distinguishable. Even though Cold looks almost the same as Temperate and also Tropical and Dry look almost the same if you suffer from a strong red-green color blindness.

Climate Classification - Blue Yellow
Climate Classification – Blue Yellow
Climate Classification - Magenta Green
Climate Classification – Magenta Green

Protanope Tools offers the possibility to color translate any image. You can just drag the two bookmarklets below to your browser bookmarks and this way you always have the two direct color translations ready whenever you come across a colorful diagram.

The best case when you colorize your own diagrams is and will always be the one, where nobody needs a separate tool to understand your message. Be aware of color blindness when you color code your own graphics and for every other case Protanope Tools will help you out.

Update: To get a better understanding of what goes on behind the scenes of these color translations, read the article on Simple Color Translation Algorithms, which reveals the two algorithms used above.

Color, What? What Color?

I just found a nice little video at YouTube about Michael, a colorblind boy. In this short little sequence the makers of the video try to describe how color blindness affects his everyday life.

This was for an in-class film project class at Adelphi University. It’s an exaggeration of our classmate’s Michael’s life living with color blindness.

The video is categorized under Comedy, so don’t take it to seriously…

Color, What? What Color?

Carnival of Colors I — Blue

A few weeks ago I decided to start my own blog carnival on a very broadly defined topic: Carnival of Colors.

Whenever you write something on your weblog in any way related to colors which you would like to include into the next release of this carnival just contact me through the contact page.

The first release of this carnival isn’t that big. I received only two valuable contributions which sums up to three when counting my post as well. Carnival of Colors I is issued under the topic…


« Thinking about blue birds there is one which comes to my mind instantly, the Blue Tit, about which I just learned that its scientific name is parus caeruleus and it is well known in Europe but quite exotic in America. If you want to learn more about blueish birds and the term cerulean visit Color Me Cerulean posted at 10,000 Birds from Mike Bergin. »

« Maybe you sometimes feel blue and are looking for a nice change. Why not give it a go by creating your own scrapbook? Check out the secrets of Design Team Member – Pam Aylor at and find your own favorite layouts. »

« My red-green color blindness gives me a lot of difficulties in naming colors. But one color I’m always quite certain about is blue which looks quite different to all other colors even to my eyes. Have a look at the Ishihara Plates Color Blindness Test here at Colblindor to learn which colors you can distinguish best — or maybe not at all. »

This was the first issue of Carnival of Colors. I hope you enjoyed it despite its shortness. See you again at Carnival of Colors II the first of next month.