Find the square with the odd shade
| Scan the grid | Look for the odd square. |
| Tap it | Correct answers add time; wrong ones cost it. |
Shade Finder fills a grid with squares of one colour, except that a single square is very slightly different. Find it, and the next level makes the difference smaller. Eventually you reach the limit of what your eyes can distinguish.
That limit is real and varies noticeably between people, and with the screen you are using. It is a decent informal test of colour discrimination, and the level you plateau at says something about both your vision and your display.
Use your peripheral vision. Staring directly at each square in turn is slow, whereas letting your gaze rest in the middle of the grid often makes the odd one seem to stand out on its own.
Scan in bands rather than randomly. Sweeping row by row covers the grid systematically, and at higher levels the difference is too small to catch by chance.
Turn your screen brightness up. At the hardest levels the difference is genuinely close to the limit of what a display can show, so a dim screen makes the task unfairly hard.
Do not guess when the clock is short. A wrong answer costs more time than it saves, so a careful scan is better than a hopeful tap even under pressure.
Small enough to approach the limits of both human vision and typical screens.
Yes. Brightness, contrast and panel quality all matter at the harder levels.
You lose time from the clock, so guessing is penalised.
It is an informal one. A proper assessment needs calibrated equipment, but the game does exercise the same ability.
No sign-up, no email, no account. Open the page and Shade Finder is ready to play straight away, on a phone or a desktop.