What kind of light brings the greatest appearance of depth in a photo.

Answer 1

Read lots:

http://darrellyoung.blogspot.com/2011/09/photography-basics-rgb-channel-and-bit.html
from
http://www.google.com/search?q=photography+basics+color+depth&oq=photography+basics+color+depth&aqs=chrome..69i57.16996j0j7&sourceid=chrome&es_sm=119&ie=UTF-8#q=photography+basics+color+depth

Answer 2

What does a shadow indicate?