Try other sources of material to get new and different colors of dye. Can you try to make yourself a complete set of homemade markers? Which materials made the best colors?
Another fun chromatography project is to use Kool-Aid® as a source of pigment. Conduct an experiment using your favorite flavors of Kool-Aid. Do some of the different flavors use some of the same coloring agents? Which flavors contain mixtures of different-colored molecules?
Some plant pigments change color when they are mixed with an acid (like vinegar) or a base (like baking soda). Conduct an experiment on different plant dyes to see which ones have this amazing color-changing ability!