Phil, a couple of pointers, you need to lengthen the mast so you don't get bladestrike on either the tail or the nose. You need a blade pitch mechanism as well. I would also suggest moving to a 4 blade system (smoother with lower disc loading), with a slightly wider chord and less twist. The tips need to be thinner and swept back. For acciracy I would also add a nickle alloy anti-erosion srtip along the leading edge of each blade. I would also thin down the gun pylon and downsize that artillery (its too huge), serious drag and vibration issues. You are also going to need a bigger vertical stabilizer to get it to see cleaner air and a horizontal stab setup as well. Widen the stance of the main gear, ground stability in rough terrain is an issue. Why most rough field operators as for skid gear systems in place of wheels (more stable on non-level terrain). Sorry for going on about this. I think you have a cool idea here but it needs some tweaks to be more believable. (yes I do design for a major civil/paramil/mil helicopter manufacturer) As for paint, flat medium to dark grey on top feathering to light grey on belly.

Pass no temptation lightly by, for one never knows when it may pass again!