My answer: not unless they are color blind.

But you and I might see things differently.

These are the opinions of a deuteranope. I reject the term color-blind because I am not blind in any sense. My life is as rich and wonderful as that of anyone; I can see bright and varied colors, meaningful and beautiful colors. But my eyes are deemed “green weak” and indeed my color perception is impaired in a few ranges.

So what?

What’s in a name? A rose by any other name would smell as sweet.

And the rose’s color is as beautiful to me as to you, even though our perceptions of the color might differ. We’re not talking about any kind of blindness.

In this article I shall use the terms normal color-balanced and non-normal color balanced. I’m happily nncb. My color balance is not normal; for that matter, neither is my handedness (left). No one calls me one-handed or manually dysfunctional, even though left-handedness presents far more problems in daily life than nncb.

Color blind is the term everyone learned, though, so I cannot resent its use. Still, consider it declared here that the expression is an insensitive one.

What’s in a test? The curse of Ishihara.

The ubiquitous color perception test was developed by Shinobu Ishihara in 1917. Still in use today (I encountered it last week in an eye exam), it is indisputably accurate and easy to administer. Not to mention cheap.

Therein lies the devilment. I contend that the low cost and simplicity of the Ishihara test has led to an undue exaggeration of its significance. For heaven’s sake, the test can even be self-administered. It requires no training or equipment, no lab reports, no protocols, no second opinions. Anybody can look at the dots and, well, you either see numbers or you don’t.

Ishihara has made us brand people as color-blind merely because it is so easy to do so.

Think about other deficiencies and dysfunctions. Tinnitus, for example. It impairs my life far more than nncb. I don’t enjoy the Philharmonic nearly as much as I used to, and I still love art museums. But there’s no quick, cheap, idiot-proof test for hearing. If there were, I might be labeled deaf as well as blind. Any of us might have deficiencies in smell, or taste, or even touch. Are your fingertips as sensitive as a normal person? Maybe not, and maybe that’s a problem, but you don’t know it because nobody tests for that.

Because we have a term that implies a severity of dysfunction, and because we have an insidiously simple test for it, we treat nncb as a significant aberration when in fact it presents far less an impairment than other conditions that are less susceptible to simple detection.

What’s a developer to do?

This isn’t at all scientific, but it seems to me that color variations among displays vary more widely than the range of colors that my eye confuses. Because I am green-weak I might have calibrated my display to boost the greens. I don’t know whether I have done this; without calibration equipment, there’s no way for me to know. So, even if you use an application like ColorOracle to get a theoretical approximation of an nncb user’s color perception, you still don’t know how the colors show up on the nncb user’s display.

I appreciate GUI developers who remember the nncb among us. I have to say, however, that there’s not much developers can do for us. Avoiding over-reliance on color to distinguish among controls sounds like a wise precaution whether you’re concerned about color perception or not. Other than that, I doubt that there’s anything you can do. We get along pretty well in the world. If 15% of your users are nncb, then I’d be willing to bet that the vast majority of them, when it comes to color, can do anything except pass the Ishihara test.