Mini Games
Color Discrimination Test
Find the one tile that is slightly lighter or darker—grids grow up to 7×7.
How to Play
- Press Start and a 2×2 grid appears. One tile is a touch lighter or darker than the rest—tap it.
- You get 15 seconds per stage; if the timer hits zero the game ends right away. A wrong tap costs one of your 3 hearts, and the clock keeps running.
- Every 2 stages the grid gains a row and column (capped at 7×7 from stage 11) and the shade gap shrinks. Your score is the number of stages you clear.
This is a game, not a medical color vision test. Screen brightness, color profile, and night mode all affect your result. To screen for red-green color deficiency, try the Color Blindness Test
Best Record
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Can you clear one more stage today?
Ranking
| Rank | Nickname | Score |
|---|---|---|
| Rank | Nickname | Score |
|---|---|---|
- |  You | - |
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Color Discrimination Test is a quick "find the different color" game. A grid fills with tiles of one color, and exactly one tile is a little lighter or darker than the others. Tap that tile before the timer runs out to move on to the next stage.
The rules are simple and the same for everyone. The first two stages use a 2×2 grid; every two stages the grid gains a row and a column until it reaches 7×7 (49 tiles) at stage 11. Every stage has its own 15-second timer, and the game ends the moment it hits zero. A wrong tap costs one of your 3 hearts while the clock keeps running. Your score is the number of stages you clear, and it goes on the ranking board.
The difficulty curve is concrete: the odd tile starts 14 points apart from the rest in HSL lightness, with a small saturation shift on top, and the gap narrows by one point every two stages until it bottoms out at 3 points from stage 23. The hue never changes—only how light and how vivid the tile is.
Because of that, this is a game, not a color vision exam. It does not test red-green or blue-yellow color blindness, and screen brightness, color profile, night mode, and blue-light filters all change what you see. If you want a screening for color vision deficiency, use the Color Blindness Test instead. When the run ends, send a challenge link and see who can spot the different color faster under the same rules.
Frequently Asked Questions
Q. How does the color discrimination test work?
A. You tap the one tile that is slightly lighter or darker than the rest. Each stage gives you 15 seconds, and a wrong tap costs one of 3 hearts while the timer keeps running.
Q. How is the score calculated?
A. Your score is the number of stages you clear. The game ends as soon as the 15-second timer for a stage runs out or you lose all 3 hearts.
Q. How hard does it get?
A. The grid grows from 2×2 by one row and column every two stages and stays at 7×7 from stage 11. The lightness gap starts at 14 HSL points and narrows by one point every two stages to a minimum of 3.
Q. Can this game diagnose color blindness?
A. No. The odd tile differs only in lightness and saturation, not hue, so it does not check red-green or blue-yellow color vision, and screen settings affect the result. For a self-check, use the Color Blindness Test; for a diagnosis, see an eye doctor.