Ralph, I would leave it natural and like Koehlers idea of coloring the flag if you use a black background as you said you were going to use. If you use a picture background I would take into consideration if the background is light, then stain it dark for contrast or you'll lose your image; and of course, if the background is a dark one leave it light. However, if you use a night backdrop (really like this one..) (possible nightfall or beginning of daybreak or with fireworks) color the flag (again) and leave it natural with just a clear finish. There. There's my nickels worth since it's obviously more than two cents worth lol