Separate colours with chromatography. Mix colours in a snack and by spinning them together.
Science content (2016 curriculum):
Chemistry: Physical Changes, Solutions, Mixtures and Separating (2, 4, 5, 6)
Physics: Light and Sound (1)
Curriculum connection (2005 science topic):
Physical Science: Properties of Objects and Materials (grade K)
Physical Science: Properties of Matter (grade 2)
Physical Science: Chemistry (grade 7)