Take any colour and keep adding black or white paint to make different tones of the primary colour. Create paintings using only these tones. As children become more controlled in mixing and blending, use a flat surface like a plate for the colour and black/white

Only use RED, YELLOW and BLUE paint

Idea: Colour Dragon/Snake. (Draw outline. Paint in blocks of primary colours. With a damp brush blend the red into the yellow, the blue into the red etc. (Wash brush each time)

As children get older, move away from pot palettes and move towards plates/artist palettes so they can create and blend more interesting colours. Consider a recipe book / chart of colours, e.g. 2 dabs of red + 1 dab of blue = maroon. Find lots of interesting colour vocabulary.