I second (or third, or whatever) the flip-flop/chameleon colours. Combinations of teal, blue, purple and pink are my favourites.
Some refinements/off-shoots of current finishes would be nice, such as:
Gibson Skyburst (a very bright blue burst done over solid white, though I've seen a couple done which were sprayed over a bright silver base instead which was very pretty):
Gibson aged/green tiger (similar to tiger's eye but with no burst and more wear to the black grain, basically flame maple dyed black, rubbed back and sprayed over with amber)
Carvin dragon burst (green-blue rather than yellow-blue; they also do a blue and purple version as a special order, which I'm very fond of)
Fender Sienna Burst (it's actually not quite as red as this and the transition from the clear middle to the burst edge is a bit softer, but it's hard to find photos of it that show that and that aren't gigantic files)
I second the purple/black burst that was posted earlier in this thread (can you guess I like purple?)
And general refinements to the service: I think the extra wide burst over option should be in the body builder (plus better example pictures of what the standard and wider burst-overs are), as should a clean line/different colour back&sides option for every finish, not just dyed tops and the Goldtop finish (so, as a random example, you could order an olympic white top with a clear back). I also think that burst-over should be available with transparent colours as well as dyes (there's been enough trans red/black burst over finishes turn up in the showcase, it must be popular enough).
The neck tint needs to be much more natural. Of all my Warmoth orders the one and only complaint I've had is that the 'vintage' tinted neck came out pretty much bright orange. Compare that to the Fender tint which is much more subtle and definitely more brown than orange.
Also, the satin nitro you're using for neck finishes at the moment rubs gloss (and subsequently, sticky-feeling) very quickly. Had that on three necks now, they've basically become gloss finishes within a months' use. Meanwhile the nitro finishes I have on four other guitars have stayed matte and very slick-feeling for years. I would suggest you look into getting hold of a better product for these satin neck finishes. On my three I've just sanded the Warmoth finish back and resprayed them with cans of light tint nitro from a local guy and this has produced a much slicker-feeling and better-looking finish than the Warmoth one.