A color wheel for the color-blind

Question

I am working on a visualization that requires the use of color to depict angular variation. Normally, I would use the HSV system (i.e. the color wheel) for coloring according to angle, but I have not a few colleagues who are color blind, and would probably have trouble with the red and green parts of the wheel.

Has anyone ever come up with a color wheel that is suitable for the color blind? I don't need it to have the same "good" colors as the usual HSV, just that I have a continuous "circle of colors". As mentioned, I'm primarily interested in deuteranopia, but schemes for other forms of color blindness would be welcome.

Searching around to the best of my ability only turned up results on "complementary colors", but none on an actually usable wheel, so I'd be grateful for any pointers.

Answer 1

There are several kinds of colorblindness, not all being equal. So to construct or find a color blindness anything one needs to be able to articulate what kind of colorblindness you mean. Therefore one circle is not enough for general work.

Image 1: Most common types of color blindness simulated on a normal color circle. Note that darkness in the circle is because they lack red. Not a different color for them just darker yellow.

There is a second consideration to think about. If you drop a color primary, like in many of the cases are doing, then you no longer have a three dimensional color field so you no-longer need to actually have color triplets and 2 values is enough. This means you no longer have a circle but rather a color line (altough it certainly is not this straightforward). Of course you can turn it back on itself but its repeating itself on the other side.

Image 2: When you normalize the color of a colorblind you get something like this (no deep research behind image just working on my memory so take it with a grain of salt). Which is not really a wheel at all just a line thats been turned back on itself.

However i don't think its necessarily a good idea to use such a system. As you realty want to design in colors that normal color sight can see but chose them so that they have meaningful contrast for the colorblind. Many design applications can simulate the most common cases colorblindness (in PS you can find them in view proof colors).

Answer 2

Basing my answer on Joojaa's observation,... we can add an extra color 'black' to one side and thus make this circle asymetrical. This would give us a color triangle for the color blind. We can't use all the 'hue', so we let 'lightness' and saturation do part of the job.

You say you can't use the HSV system. Well, you can. But in an ordinary color circle, it's only the H(ue) that changes. We can also use the S and V (saturation and lightness) to find other round-tours in color space.

From here, we can start creating a color circle: Using Illustrators Blend tool (specifying 1 step), we can first make a color triangle with yellow, black and cyan/blue on the vertices, then blend these colors into a color hexagon and once more to make a color dodecagon. If twelve colors is not enough and a dodecagon is to edgy, you can use the blend to once more (this time with the 'smooth color' setting) and use a clipping-mask to mask a circle shape.