One band of the flag is blank. Rebuild its colour on the sliders: closer is better.
A daily flag-colour puzzle. One band of a flag is blank, and you rebuild its colour on hue, saturation and brightness sliders. It's harder than it sounds: plenty of flags share a red, but very few share the same red. If you've played Geopaint, it's a similar idea: getting a flag's colours right from memory, here one band at a time on hue, saturation and brightness sliders. (Geographys isn't affiliated with Geopaint.)
How it works
1One band of the flag is blank. The country and which band it is are named under the flag.
2Drag the sliders to rebuild that band's colour. The flag updates as you drag.
3Lock it in to see the real colour. Your score is how far off you were, measured the way the eye sees colour: lower is better and 0 is perfect.
Tips
Set brightness first. Most misses are colours that look right but are too dark or too light.
Then hue. Blues run from the navy on the UK's flag to Argentina's sky blue, and reds from scarlet to deep crimson.
Compare against the rest of the flag. The other bands are shown in their real colours, so they set the scale.
Recall the specific flag, not its type. Flags that look alike rarely share exact shades.
Questions
How is it scored?
By the distance between your colour and the real one in the CIELAB colour space, which is built to roughly match how people see colour differences. 0 is perfect, so lower is better.
When is there a new daily?
Every day at midnight where you are. Everyone gets the same puzzle on the same date, and practice rounds are random.
Why the same red isn't the same
Some countries set their flag colours down exactly, with official colour codes, while others only name them, so the red on one maker's flag can differ from another's. Even with exact codes, two flags described with the same colour word rarely match.
Eyes are better at comparing colours than remembering them. The other bands of the flag are shown in their real colours, so use them as a reference rather than working from memory alone.