What this test measures
One tile in the grid is a slightly different shade from the rest, and the Color Match Test asks a single thing of you: find it and click it. The grid starts at 2×2 and grows every three levels until it reaches 6×6, while the gap between the odd tile and the others shrinks as you climb. Early rounds separate them by roughly 15 percentage points of lightness; by the late levels the gap can be as small as 2 points, which is the floor. You get three lives. A wrong click costs one, and your score is the last level you cleared.
Two different abilities decide how far you get. The first is discrimination, the smallest lightness difference your eye can resolve, which vision researchers call a just-noticeable difference. The second is visual search. On a 6×6 board you are checking 36 tiles, and a difference you would spot instantly in a pair of side-by-side swatches can hide in a crowd. The hue is randomised every round, so you cannot memorise one colour and coast. Each level is a fresh comparison.
Why there is no percentile here
Most tests on this site tell you how your result compares with other people. This one deliberately does not. Nobody has published a normative distribution for a browser tile-discrimination game of this design, so any percentile we showed you would be invented. There is a deeper problem too: the thing being measured is not cleanly you. Whether you can separate two shades that differ by 2 points of lightness depends on your panel, its brightness setting, its colour profile and the light in your room, and those factors swing the result more than the player does. A percentile here would mostly be ranking monitors.
Clinical colour tests such as the Ishihara plates and the Farnsworth-Munsell 100 Hue test earn their numbers by controlling what a web page cannot: calibrated or printed stimuli, viewed under standardised lighting. Without that control, comparing one person's score with another's is noise dressed up as data. The comparison that does mean something is you against yourself, on the same device, under the same conditions.
Your screen is part of the test
The same person can score several levels apart on two devices in the same afternoon. Here is what changes underneath you:
- Panel type and colour depth. A decent IPS or OLED panel driving 8 bits per channel renders a 2-point lightness step as two genuinely different colours. A cheap 6-bit panel may round both tiles to the same output. When that happens, no amount of staring helps, because the difference never reaches the screen.
- Brightness. A dim screen compresses shades together, especially darker ones. Raising brightness stretches them apart again.
- Night shift and blue-light filters. These pull the whole display towards orange and can flatten the very differences you are hunting for, most noticeably on cool hues.
- Forced dark modes. A standard dark theme leaves the game's colours alone, but "smart invert" and forced-dark features on some phones recolour web pages and can distort the tiles.
- Ambient light. A window behind you lays a sheet of glare over every tile. Reflections raise the black level of the screen and eat subtle contrast.
- Viewing angle. On cheap panels, colours shift as your eye moves off-axis. A tile in the corner of a large grid reaches your eye at a slightly different angle than a tile in the centre, which is enough to fake a difference or hide a real one.
This is also why your phone score and your laptop score rarely agree. The two devices have different panels and different automatic behaviours, and a phone's auto-brightness can quietly change mid-game when a cloud passes the window.
Colour vision, and who this test excludes
Around 1 in 12 men and 1 in 200 women have some form of colour vision deficiency. The other five tests on this site are built so that colour is never the only signal: shape, position, motion or text always carries the information as well. This test is the one exception, and the reason is simple. Colour discrimination is the thing being measured, so there is nothing else to fall back on. If you have a colour vision deficiency, some rounds of this game will be unfair to you in a way the other tests are not, and we would rather say that plainly than pretend otherwise.
What this test cannot do is diagnose anything. A low score here tells you nothing reliable about your eyes, because a bad screen produces exactly the same result. If you suspect a colour vision deficiency, the real instruments are the Ishihara plates and the Farnsworth-Munsell 100 Hue test, administered by an eye-care professional under controlled lighting. A browser game is not a substitute for an eye examination, and this page should never be treated as one.
How to see the difference for longer
Sweep the grid in a fixed order, row by row, rather than letting your gaze bounce around. Staring hard at one spot is counterproductive: your retina adapts to the shade you are fixating on, and after a few seconds the whole board smears into sameness. Keep your eyes moving and let the odd tile pop out in peripheral vision, which is surprisingly good at catching a mismatch.
Work the borders. Two shades that look identical when you glance between distant tiles are easier to separate along the seam where neighbouring tiles nearly meet, because the visual system is far better at comparing adjacent regions than remembered ones.
Set the stage before you start. Turn off night mode, raise your screen brightness, face the screen straight on, and get glare off the panel. If you have been playing a while and the tiles have started to look uniform, look away at something distant for ten seconds; the adaptation fades and the differences come back.
And accept the ceiling honestly. Once the game reaches the 2-point floor, whether you can continue is decided largely by your display. Technique buys you levels in the middle of the run, not at the end of it.
Frequently asked questions
Does this test colour blindness?
No. It cannot detect or rule out colour vision deficiency, because a browser has no control over your screen or your lighting. A poor score is at least as likely to mean a poor panel as anything about your eyes. If you want an actual answer, book an eye examination; proper screening uses tools like Ishihara plates, not tile games.
Why is it harder on my phone?
Several things stack up. Phone tiles are physically smaller, so each colour sample covers less of your retina. Auto-brightness changes the compression of shades without asking you. Night-mode filters are more commonly left on. And holding the phone at a slight angle shifts colours on many panels. Turning off automatic brightness and filters, and holding the phone square to your face, usually recovers a few levels.
What is a good level?
There is no published norm to compare against, so we will not pretend to hand you one. The honest benchmark is your own history: play a few runs on the same device in the same lighting, note your typical score, and treat improvement on that setup as real. A score achieved on a bright, well-calibrated monitor and a score achieved on an old laptop in sunlight are not the same measurement.
Can I get better with practice?
Partly. The raw discrimination threshold of your eye is fairly stable from day to day, but visual search improves with repetition: you learn to scan in order and to use tile borders instead of staring. Most early improvement comes from search strategy and from fixing your setup, not from your eyes changing.
Why do the tiles all start to look the same after a while?
That is adaptation. When you stare at a field of similar colour, the photoreceptors responding to it fatigue and your sensitivity to small differences in that region drops. It is temporary. Look away for a few seconds and the board separates again, which is why short breaks between runs are worth more than grinding.