Welcome to Librarium Online!
I have purchased the megaforce (space marine) and i do not know whether i want to do a blood ravens color scheme or green with white, any advice on which you think would look better would be greatly appresciated
Dude, do the Raven Guards and get the Captain Shrike model, assault oriented Space Marine army! I think the second paint scheme is theirs.
Raven Guard are black and white.
As to the question; basically you're asking us to pick you a colour scheme? Sorry but that just annoys me, ask if the shades look right and that but not to pick which one looks better. Nothing I can do about it just a pet peeve.