The big problems is when the plane is back lit. Our field is orentated so the left side is basicly east. We have do do our flying in the morning, before noon mostly as the winds pick up really bad starting around 10 to 11. That means we generally fly off the right end of the runway because the plane is always iluminated from the left. When it gets cloudy, the white of the clouds overides the front iluminaton and all you have is a silhouette.

The color isn't important, the contrast is. Black and white is probably the best. Light blue blends with evertything. My first plane had bright blue on top of the wings and missle red on the bottom. I thought it would be a good visible contrast. After crashing it a couple months back, I had to replace the wing so I selected teh White/dark purple bars on the bottom. As you don't very often see the top of the wings, I got a bit carried away there, but still kept the stark contrast difference to the bottom.

Don