Let dry before continuing. Lay the filter on the top of a cup with a little water and let the strip touch the water. The strip should reach the water, but the drop of dye should be above the water level. As water soaks up the strip and onto the rest of the filter, it carries different dyes at different rates, thus separating them. Many variations on chromatography are used to analyze chemical mixtures of all sorts.
Many colors consist of mixtures of pigments.