How Good Is Your Hue Sight?
Hues are little increments in tone or in true color. X-rite put up a little twist on the old numbers in the dots hue test. And put up a challenge where you can test how well you can discriminate hues from each other. It was far from trivial on a calibrated monitor.
Of course, the other side from a perfect score is being color blind.
You can take the test yourself here. How did you score?