Colordle asks you to rebuild a colour that stayed on screen for five seconds. Once the target disappears all you have is memory: you set the red, green and blue channels one by one and try to land the same tone. The same colour opens on every screen in the room, so everyone is chasing the same target.
How it works
When the round starts the target colour fills a large square and stays for 5 seconds. Then it disappears and three sliders take its place: R, G and B. The target is drawn from the 30-225 range, so it is never pitch black or blown-out white; every round gives you a genuinely distinguishable colour.
After you submit, the game waits for the other players. Once everyone is in, the result opens and your colour is shown next to the target. That side-by-side makes the miss obvious: usually one channel is close and another is well off.
Scoring
Your score is the distance in RGB space. The smaller the gap between your triplet and the target triplet, the better. After everyone submits, players are ranked by that closeness: first +3, second +2, third +1. Even if nobody nails it, the round still produces a winner.
Why colour memory is weak
The eye separates millions of colours, but memory stores a colour as a category rather than a value. Five seconds later what you remember is "a blue leaning towards turquoise", not that blue's exact numbers. On top of that the RGB channels are not perceptually equal: green carries most of the brightness and blue carries almost none. Missing the blue channel by 20 units is barely visible, while the same miss on green visibly breaks the colour.
Tips
Lock the hue first, brightness second. Decide whether the colour is warm or cool within the five seconds; the channel values come later.
Find the dominant channel. In most colours one channel clearly leads. Place it first, then move the other two relative to it.
For muted tones, pull the channels together. Washed-out colours usually sit where all three values are close.
Do not change screen brightness mid-round. The conditions you saw the target in should match the conditions you guess in.
Trust the first impression. Fiddling with sliders for too long drags you away from what you actually remembered.