Color Blindness and Brand Colors: Playing On Brand with Color Vision Deficiency

About one man in twelve doesn't see color the way most brand palettes assume. If that's you, a game like On Brand, where you restore a logo's true color from memory, can look like it was built for someone else's eyes. It wasn't designed to shut anyone out, and there are good ways to play it. They start with knowing what your eyes do and don't pick up, and what the score is actually measuring.

Among people of Northern European descent, about 1 in 12 men and 1 in 200 women have red-green color vision deficiency, the common kind. Rates are lower in many other populations. The genes for the red- and green-sensitive light pigments sit on the X chromosome, which is why men, with one X, are affected so much more often than women (Color blindness).

It has a long paper trail. The chemist John Dalton described his own color vision in 1794, closely enough that red-green deficiency was long called Daltonism. The best-known screening test, the dotted plates designed by Shinobu Ishihara, dates from 1917 (Ishihara test).

One famous brand color has a link to it. Mark Zuckerberg is red-green color blind, and he told The New Yorker in 2010 that Facebook is blue because blue is the richest color for him.

Normal color vision uses three kinds of cone cell in the eye, tuned to long, medium and short wavelengths of light, roughly red, green and blue. Color vision deficiency comes in a few forms:

• Anomalous trichromacy: all three cone types are there, but one is shifted. Deuteranomaly, a shifted green-sensitive cone, is the most common form of all. Many people with it don't know they have it until they are tested.
• Dichromacy: one cone type is missing. Protanopia lacks the red-sensitive cones, deuteranopia the green-sensitive ones and tritanopia the blue-sensitive ones (Dichromacy).
• Monochromacy: seeing little or no color at all, which is rare.

Red-green deficiencies (the protan and deutan types) are by far the most common. Blue-yellow deficiency (tritan) is rare and affects men and women about equally.

For someone with red-green deficiency, the colors that are hardest to tell apart are the ones that differ mainly along the red-green axis while matching in lightness. In logo terms, the usual trouble spots are:

• Red against green, and both against brown or olive when the lightness is similar.
• Orange against yellow-green.
• Blue against purple, because the red share of a purple is the part that fades.
• Pink and magenta against gray or a light blue.
• Teal against gray.

People with a protan deficiency also tend to see reds as darker than others do, which can make a strong red read as a dark brown.

What is usually preserved is just as useful: lightness, and the blue-yellow axis. A red-green deficient player can generally tell a dark color from a light one, and a blue from a yellow, as well as anyone.

On Brand scores your color with CIEDE2000, a standard color-difference formula. That formula is built on the CIE's standard observer, a model of typical three-cone color vision. So the score answers one specific question: how different would these two colors look to a typical eye?

That has a direct consequence. If you have red-green deficiency, a brown you mixed and the brand's red may look identical to you and still be far apart for the formula, and the score will say so. The score isn't wrong, and it isn't judging you. It is reporting a difference you may not be able to see directly, the way a thermometer reports a temperature your hand could only guess at. How CIEDE2000 scores a color explains the formula.

The good news is that much of On Brand can be played with knowledge and numbers rather than raw color perception.

1. Use what you know about the brand. Most people can tell you a famous brand's color by name, even if they could never pick its exact shade: the red cola, the golden arches, the blue social network. If you know the family, you can place the hue by number.
2. Set hue by the numbers. Each slider's value is shown beside its name. Hue is an angle: 0 is red, about 30 orange, 60 yellow, 120 green, 180 cyan, 240 blue and 300 magenta. What each slider does lists the game's color bands in degrees.
3. Count the ticks. With sound on, the hue slider ticks every 15 degrees, so four ticks is 60 degrees. You can move a known distance without judging the color at all.
4. Lean on lightness. Brightness and the overall lightness of a part are the cues your eyes keep. Compare the part with the logo's other parts, which keep their real colors, and match how light or dark it sits among them.
5. Use the starting color as a clue. The wrong color always starts at least 60 degrees round the wheel from the answer. If the slider reads 120 when the part arrives, the answer is not between 60 and 180.
6. Learn from the readouts. The reveal labels your color and the brand's with their hue, saturation and brightness numbers. Over a few rounds you can learn which numbers you tend to miss, even if the two circles look the same to you.
7. Choose a collection you know. Famous, with household names, is where color names carry you furthest.

The keyboard helps with precision: on a focused slider, arrows move one step, Shift and an arrow ten, and Home and End jump to either end, so you can type your way to an exact hue.

A good logo survives in one color. The best brand identities are recognizable by shape alone, and accessibility guidance agrees: the Web Content Accessibility Guidelines say color should not be the only visual way information is shown (Use of Color). If two colors in a design only differ along the red-green axis at the same lightness, about one man in twelve may not see the difference. Browser developer tools, including Chrome's, can simulate the main types of color vision deficiency on any page, which makes this easy to check.

If reds and greens, or blues and purples, often seem to swap places for you, an optometrist can test your color vision properly in a few minutes. Online plate tests are a rough first look, but screens vary too much to give a diagnosis. Either way, try a round of Famous with the sound on and the hue numbers in mind, and see how far knowledge alone can take you.