`Culler Mode uses the shape of the brush, cullered with the current foreground.
Color Mode uses the shape of the brush, colored with the current foreground.
A multicolored brush image becomes a single colored brush to paint with.
`Culler Mode is useful for creating different shadoe effects.
Color Mode is useful for creating different shadow effects.
Remember, F1, or Matte Mode, returns a brush to its original form.