Yes, green looks better than black. I'll have to see if they have a dark blue that will closely match my blue Civic.
I'm thinking of mocking up something on my '06 Civic using coat hangar wire and cardboard. If it it works, I'll try the same thing using sturdier materials.
Problem is, even if I paint the cardboard on both sides, one rainstorm will probably ruin them.
As for the roof rack, I'd use RTV to seal the holes. Will seal well, can last a long time and if you have to remove it, well, any screw or bolt can work its way through the stuff no problem.