Colour by Number is a painting game with Galah, a rainbow cockatoo who loves bright colours. Every picture is split into parts, and each part shows a number. Tap a paint pot, then tap every part with the same number, and the paint ripples out from your finger right up to the lines. The first pictures have three pots and big round parts, and the parts for your pot glow softly, so even a four-year-old finishes them. Later pictures have up to six pots and smaller parts to find. When a colour is done its pot gets a tick, and when the whole picture is painted it comes to life. Each finished picture wins a new brush and turns to a new place: a flower garden, the seaside, snowy hills, a playroom and a starry night.