I used a version of the Carnival poster I found in the HI-Res Poster Art thread. It seems to be a slightly different version of the artwork, perhaps an early draft. I personally like the colors in this alternate version. You can really see that the twin orbs in the bottom right are supposed to be Tatooine's suns. But now that you mention it, Luke and Leia are a little too red and dark. If you could help me find a hi-res copy of the version you used for the label, I might try to fix Luke and Leia.
Any recommendations for the text on the back?