Shadows

[Freeman14]

Hey guys,
I need some advice about shadows. When I'm fishing under a bridge, and there is a clear shadow "line", should I cast into the shadow, slightly outside or what??
Same question goes for trees and other structure alike.

[Paps]

During the day, cast deeper into the shadows and bring your lure back into where the light and shadows meet.

Sunnier it is the deeper in the shadows the fish should be!

[Freeman14]

Cheers
Do you think lure colour would matter?
Also, what retrieve/technique would you reccomend?