I've been working on this one in my spare time. It's a reference to an episode in season 2 (the new series). It's still a WIP, but the issue I'm having is that it's already well over 6 colors, and I'm not sure what changes I should make to bring it down.

Do "colors" include shades of gray, or is any gray lumped under one color? If so, that'll help a bit. As of now, I'm unable to go further until I work the color issue out.
Also, I noticed the submission guidelines say all submissions should be 600x800 and no greater than 500kb. Shouldn't submissions be 300dpi if they're designed for printing?

Do "colors" include shades of gray, or is any gray lumped under one color? If so, that'll help a bit. As of now, I'm unable to go further until I work the color issue out.
Also, I noticed the submission guidelines say all submissions should be 600x800 and no greater than 500kb. Shouldn't submissions be 300dpi if they're designed for printing?
It's difficult getting down to 6 colors once you already have a design almost basically done.
You could try to greyscale it as well.
I really like it though Good luck!