This looks great. The color palette complements the design well, but maybe try adding white as an additional color. You could also try changing the font color on the back (brown side) to white for better legibility.

I really like the color palette of this design. I think the design flows well together, and you utilized illustration in an appropriate, balanced way. Maybe its the colors clashing, but the text of Jennifer's Heaven is a little bit hard to read just because the thinnest points seem to get lost. It could just be an image quality thing but overall, super good work!