This is a fun project that can be altered to suit all different age groups. I have done this in a 3rd grade classroom. Each student got to prepare their own samples. It was a big hit!
This activity involves the use paper chromatography to separate the colors/dyes use in candy coatings of a Reese’s piece or an M&M. We choose to use the “dark brown” varieties of each candy and had the students compare the components by chromatography. It was a great way to introduce “mixtures.” Before doing the chromatography with the candy coatings, we introduced students to the concepts of chromatography using food coloring (both individual colors and mixtures of the food dyes).
Here are some references for related activities that I found on the web:
…and there are even methods of dye extraction and separation for more advanced students (high school or college).