I wish I was more artistic! I would definitely paint the outside.. but I don't trust myself to do a good job with it. My sister has done it on a couple fish tanks and it really does come out great. And I really would like to keep the Styrofoam for insulation. If taping it doesn't work then I'm definitely going to consider more options. I've seen those cool panels that grow plants in the right humidity? I'd have to look them up again. But thanks for the advice! If all else fails I'll commission my sister to paint the background for me!