I’m slightly obsessed with the version of “True Colors” from the Glee Vol. 2 soundtrack, a cover of the lovely Cyndi Lauper tune. But while I think this song manages it skillfully, I would use the expression “true colors” with caution. It’s really evolved to have a negative connotation, meaning hidden faults or questionable motives, e.g. “His aide’s candid memoir reveals John Edwards’ true colors — the senator was willing to lie in order to preserve his presidential bid.” I’m not saying it can’t ever be used as a compliment, but if you must, make sure the context is very clear.