I have some homework assignments to practice with watercolour. I have only 6 colours: 2 different yellows, 2 different reds and 2 different blues. 3 of them more bright and 3 of them more transparent. The assignments are about mixing the colours and see what effect they have on you and on each other.
In the first 4 ones I had to mix the reds, blues and the lightest yellow to see what effects it had when you mix them in different ways. Using lines, curves, from the middle and spiral.