Color

A colour memory test with the honesty to admit it is a memory test. A single shade fills the card while a counter labelled Seconds to remember runs down. Then it disappears and you have to rebuild it from nothing using three sliders for hue, saturation and brightness. Five colours per run, scored out of ten each, and the game's own pitch is that humans are simply bad at this.

1. Pick a difficulty from the toggle. It controls how long you get to look, and Brutal is labelled on the page as not fun.
2. Start a solo run. The first colour fills the card with a countdown on it.
3. When it vanishes, drag the three vertical strips down the left edge of the card to rebuild it, then hit the target button to lock in.

The premise is a fact about human perception rather than a puzzle gimmick: you can identify thousands of colours side by side and reproduce almost none of them from memory. This makes that concrete in about ninety seconds, hands you your HSB next to the real one so the failure is measurable rather than vague, and then insults you about it in one dry line. Free, no account, three difficulties, and a daily that everyone on the planet plays on the same five colours.

Your attempt sits directly above the original in one card, which is the cruellest possible presentation of a near miss, and both carry their HSB values so you can see exactly where you drifted. The score runs to two decimals, and underneath it the game files a one-line verdict on your effort. A 5.99 gets called the gentleman's C of colour; a 1.76 gets told it brought the wrong answer to the right question.

Solo

Five colours at your chosen difficulty, replayable as often as you like.

Daily

Five colours, the same for every player, one shot. A countdown on the screen shows how long the current day has left.

Multiplayer, live

Host a round and play it at the same time as your friends.

Multiplayer, challenge link

Send a link and everyone plays the same five colours whenever they get to it.

• Name the colour out loud while the timer runs. Verbal encoding survives the blackout better than a raw visual impression, and the sliders are hue first, so having the word already decided saves the seconds you need for saturation.
• Set hue before you touch anything else. It is the one dimension where being wrong is unrecoverable, whereas a mix that is slightly too pale still scores.
• Watch out for the dark end. Very dark and very desaturated colours read as almost identical when you are recalling them, and both sliders sit near the bottom of their strip, so small handle movements swing the score a lot.