Need help with this

can anybody tell me how you get brushes to be diff colors like this?
http://img185.imageshack.us/img185/3...izecopynn2.png
the guy that showed me this said something about a canvas but i have no idea what it is.

This is a begginer's effect.

Anyways its called color balance. First brush as desired (sigh I really hate when people use dl brushes). Then go to Layer > New adjustment > Color balance. Play round with the colors and then AS YOU HAVE THE COLOR BALANCE layer selected BRUSH BLACK the parts you want to erase. Then add another color balance with different colors and brush black what you don't want.

Also a simple yet uncontrolled effect is to create a whole bunch of different color balance layers and apply different colors to all THEN to each apply a different FILTER > render > clouds (make sure your colors are black and white) this adds soft rounded brushes randomly and yeah..

And he might have used a different technique but thats my way of doing it.

yes there are 3 other ways to do it.
but that one seems easy enough