Monochromatic painting

You need:

1. white drawing sheet A3 size
2. tempera paint
3. brushes
4. black marker

Children choose a geometric shape and draw this overlapping and in different sizes on their sheet.
Then they choose one colour tempera to colour their shapes. Mixing is only allowed with white and black, because the painting has to be monochromatic.
When ready, outline everything with black marker.