Flag Shade

A country's flag appears with one of its colours missing.

Use the three sliders — hue, saturation and lightness — to set that colour to what you think it really is. The flag updates as you move them, so you are matching from memory, not copying a swatch.

Each round is scored from 0.00 to 10.00 using CIEDE2000, the industry standard for perceived colour difference. Five rounds make a session, for a maximum of 50.00.

Every session deals five new flags at random.