coloring

Do you guys prefer coloring characters as a single color? or do you prefer filling up a cup of different colors? for me I've been filling up a cup with different amounts of colors for when I color characters.

The idea is simple, a character does different things throughout their life, and each of these actions correspond with a different mana. This means that the characters essentially fill up their cup with different colors as time goes on. A character can start as a mainly white mana character, like let's say there's an angel that's 100% white colored mana, but then they fall into darkness, and their cup is then increased by double and now you fill it with the mana that they received and in this context it's black mana, so now their cup is filled with white/black mana at 50% white, and 50% black mana.