RE: What colour?
Good color schemes. They should stand out well.
Golf-lake, we fly in a valley and there is a lot of bird activity. The birds that stand out the most are the white ones. On a cloudy day, the opposite seems to be true, the vultures stand out first.
I've got a new plane with only two flights on it, both white knuckle ones. It is a Pheonix Fun Star. The plane is covered in yellow transparent covering. Before it goes in the air again, it gets a fesh covering of either white with Marron or black bars on the lower wings or Yellow with the same. Also the rudder and vertical will be contrasting colors.
When I first started, my instructor pointed out that if you flew with the sun behind you, your ability to see the plane was better. This isn't because the sun is in your eyes, but the cloudless sky is a different color away from the sun. If you are going to fly in close, that isn't to much of a problem, but flying high and away, it is very important.
I've lost three planes due to becoming disorentated and two of them were on cloudy days with the sun at my back, the other was a clear day with the sun in my face. I wasn't sun blinded, but I lost contrast on the plane and after that, it was pick up the pieces.
Cloudy days are a real problem for me. As is the foggy mornings we have. If I don't have a mostly sunny day, I don't fly.
Don