I'm thinking of what colors might correspond w what enneagram types. For example, my mom is E9 sp/so (EII), and her favorite color is light blue...which seems like a great match for her type.
Here're my thoughts:
E1 -- white; light gray
E2 -- coral; hot pink
E3 -- bright, deep green; reddish orange
E4 -- purple; silver
E5 -- dark blue
E6 -- orange; yellow
E7 -- yellow
E8 -- black; deep red
E9 -- blue (various shades, depending on subtype, stack, etc.)
I have synesthesia, but I tried not to let the colors the numbers as numerals are influence this too much.