This was my entry for the Spirit at Troy challenge at AstroInfo (challenge rules here).
It wasn't easy to find a proper palette. All Mars images produced so far are false color, variously rendered for different scientific or outreach purposes. So there isn't really a set color atmosphere that could be unequivocally related to Mars.
I found huge inspiration in this amazing piece by raynoa. It was actually hard not to rip those colors! ;) There are amazing sub-palettes in it, at least 4 different which would make beautiful martian colors.
Instead I downloaded a number of Mars pictures, which I color-reduced and tweaked in all possible manners until I had some interesting stuff. I went for the upper left palette as a start, which I got mostly from the indexed+tweaked version of this panoramic photograph.
I wanted to include a martian sunset. It wouldn't fit with the foreground light and color though, too bad. Those inverted sunset colors are just so beautifully outlandish.
I've included 6 hidden items in the image. Some are Mars exploration related, kind of.
Can you find them? I'll give some clues after a while ;D