what color would a german bomb be. I'm not sure the weight something around an amercian 500 lb.

Hi AutoFix,
A good question, I would like to know myself. I believe they were sometimes painted the same as the underside of the aircraft that carried them, i.e. RLM 65 light blue. I don't believe that they were ever painted black, as some kits would have you do. If they were painted a dark colour it would most likely be RLM 70 blackgreen, the same colour as German aircraft propeller blades. This is the colour I paint mine, until I find out differently that is. :-)
HTH
Mal

Specifically - ?? Can't say for sure. I do agree with Holdfast, on going with the same color as the underbelly.