Color Test
Spot the one tile with a slightly different shade as the grid grows.
Find the different tile
One tile is a slightly different shade. Pick it to go up a level. Every level the grid grows and the difference shrinks. You have 3 lives.
Personal bestNone yet
How to use
Press Start. A grid of tiles appears, and exactly one tile has a slightly different shade.
Pick the different tile with a click or a tap. With a keyboard, move between tiles with the arrow keys and pick one with Enter or Space.
Each correct pick takes you up a level. The grid grows from 2 by 2 to 7 by 7, and the two shades move closer together.
A wrong pick costs one of your 3 lives and outlines the right tile. The test ends when all lives are used, and your score is the level you reached.
FAQ
How are the colors chosen?
Colors are generated in the OKLCH color space, which is designed so that equal numeric steps look roughly equally different. The base color gets a random hue with moderate lightness and saturation, and the different tile is moved by a set distance in OKLab. That distance starts at 0.16 and shrinks by 12 percent per level down to a floor of 0.012, so a level is about equally hard whatever the hue.
Is this a color blindness test?
No. It is a game, not a medical test, and it cannot diagnose color vision deficiency. Most of each difference is in lightness, with a smaller change in saturation, so people with red-green color vision deficiency can play, though some levels may feel harder. For a diagnosis, see an eye care professional.
Does my screen affect the result?
Yes. Brightness, contrast, color profile, night light or blue light filters and viewing angle all change how close two shades look. Compare results on the same screen with the same settings.
What counts as a good score?
There is no standard benchmark for this game, so the most meaningful comparison is your own personal best on the same screen.
Is anything uploaded?
No. Everything runs in your browser, and your personal best is saved only in this browser's local storage.