I think the reason the wings on the Crystal Power wands were different colors was because of the background colors. They were reflecting the colors off the white wings. (:

After analyzing the GIF some more, I came to that conclusion, too.  Though if it’s the lighting casting colored shadows on the wings, then I’d think that the shadows on each girls’ hands would be tinted the background color as well, but they aren’t.

So I think I’m going to interpret it as the wings being very subtle pastel colors. :)