We thank Elena Beatriz Abraham (a teacher from Almería, Spain) for sending this idea.
A game we play in Argentina to practise the colours is "Veo, veo...", or "I see..."
The teacher chooses an object and says its colour, and the students have to guess which object it is by saying all the things they can see of this colour.
The student who says this object wins and has to go on the game.
It's also good for practising different kinds of vocabulary at the same time.