There are some photos that can not be adequately critiqued, this is one of them. You captured a likely once in a lifetime shot, and you did it well, you should take pride in that alone. Any time I have attempted to photograph a rainbow, it is gone before the lens cap comes off, or I can not get the color right. You captured two flawlessly.

I do like how the picture is at the angle that it is. It gives is a sort of surreal sense, in stead of just, "Oh look, there is a double rainbow." It is almost as if the viewer is in flight. The use of the angle also helps to place both rainbows at ideal focal point in the frame.

Well done.