It...made sense...

Okay, symbolism...symbolism
white= pure
Black=tainted or evil
Gray= a mix of the two perhaps?

Light kind of changes, going from white to gray to black to gray to white again. Gray area is the realm in which things are unsure, usually coming in the teenage years when they find out black and white, good and bad, are blurred.
So...Near could be speaking of Light, or even Mello, who uses the mob and other criminals to do his bidding. Maybe even both. Are these the two people to whom you refer...?