A contrast between an object and its surrounding
can either stress the importance with a high contrast or hide it via low
contrast..
The following pictures shows bright (colored)
objects in front of a dark (colored) background ("Low-Key" environment).
by Detlev Franz
Obviously this will also work the other
way round as well - just place the quite dark main subject into a quite
bright surrounding. Dark object in a "Hi-Key" environment.