Most visiable color to cover plane
Mapper, it looks everyone has their own opinion on what works best for them. Probably one of those things where you're going to have to decide what works best for you!
Suggestion: make up some color samples about the size you think you'd be looking at in the air. Set them up maybe 300 to 500 feet away and see what your eyes tell you. Try it on a bright, sunny day, a cloudy day, and even at dusk and see what works best for you.