Thank you everyone for the ideas. I'm gaining a lot through this. I especially like what you've done with that little mound on the right side. Surprising how that vague tone helps. I think I'll adapt that a bit. I'd also toyed with the idea of making the sun the same shade as the sand. It would certainly save me an extra tick on my color count.
And Geraduatuza, thank you for the remix there - unfortunately, it's impractical since I'm trying to keep my color count as low as possible, and doing everything entirely by hand (pixel for pixel). It looks cool, I'll certainly give you that, but doesn't really work for my purposes. Thank you anyway!

Aaaand... Implemented. Still have the extra tone for the sun. I'm still debating on that one. If I keep it, I may put some highlights on the sand using it.
And Geraduatuza, thank you for the remix there - unfortunately, it's impractical since I'm trying to keep my color count as low as possible, and doing everything entirely by hand (pixel for pixel). It looks cool, I'll certainly give you that, but doesn't really work for my purposes. Thank you anyway!
Aaaand... Implemented. Still have the extra tone for the sun. I'm still debating on that one. If I keep it, I may put some highlights on the sand using it.