Why do some colors rise farther on the filter paper than others?
You may have got a quicker response in Chemistry, but here goes...
Chromatography is a chemical separation technique for coloured pigments in dyes that separates them according to their partial solubility in the solvent (often water in school labs.)
The colours that rise furthest are those that are most soluble, so they form the strongest bonds with the solvent (still pretty weak, but the principle is correct.)
I often use the analogy of children carrying shells back up the beach. They pick up all the shells they can, but then gradually drop the ones they are least attached to, keeping only their favourite ones to show Mummy and Daddy at the top. Does that work?