I've been building for 4 years, and it seems like every year, I have a different color in mind.
When I started, Toxic Orange as found on the dodge charger/challenger was my vision.
The orange colors have aged, and so have I, so I started swaying towards a dark metallic gray (especially magnetic gray like frankb)
This year, I got the car registered, and have been driving it in the bright red gelcoat, enjoying and appreciating red. I also like the idea that other cars will more easily see the bright red, low profile, light weight roadster before making an ill-advised maneuver in front of me. However, having driven a burnt orange mustang for a decade, I know that argument is a fallacy.
If I painted today, it would be magnetic grey with a bright red stripe (similar to the summit racing roadster). Maybe next year, it'll be flipped to bright red with a metallic stripe.
And of course blue always looks good. My wife has steadfastly held to this color preference, and maybe I'll cave in to her preference before it is finally painted!
Bottom line
automotive paint, these cars seem to look good in any color.