Ask children to choose either a famous cartoon character or a favourite teacher and photocopy a photo of it / him / her onto A4 size coloured paper.
Once you have given children five copies (at least) of the personality, ask them to cut (younger children) or tear around the different elements.
For example: have a blue background, red face, green shirt, yellow hair and eyebrows… The more, the merrier.
Each child should be able to complete 2-3 different colour combinations. This idea fills a nice amount of display space, and you achieve a weird and impressive effect.
Don´t forget that Andy Warhol’s Marylins were in tribute to her after her death.