Flag Fill

Flag Fill started on 15 June 2026 and numbers its puzzles; 18 October 2026 was #126, the flag of Sierra Leone. The puzzle names the country, so the question is not which flag it is but exactly what colour the missing part is: the precise yellow, red or blue that the flag uses.

The missing section shows as a grey checkerboard. Below the flag sits a colour picker with a saturation square, a hue slider, a hex field and a row of quick swatches. Choose your colour and submit, and the game shows your guess beside the real colour and a score out of 100.

One guess is all you get. The game keeps your streak, average score and score distribution on your device, and an archive lets you play flags you missed, without affecting your stats. It is free in the browser, with no ads and no sign-up, and works the same on a phone as on a desktop.

It suits players who like colour games such as Hueman or The Daily Hue and know their flags, since knowing a flag has a blue stripe is only half the answer.