Thanks for the additional feedback about the terrain tiles. There's a lot of subjectivity that can go into this, and I think part of the problem is that there's not really a set "theme" for the geology of the hypothetical planet. (Is it full of iron, silica, sandy-windblown, or frozen methane, etc...)
For the blue/purple shift, I believe there's a whole 'nother planet tile set planned for such a view. Something in the white/gray/bluish tile set (but I defer to Leeor). I can tint things more orange/rust and see how that comes out.
Also, from what I've experienced while trying to diversify color a bit, the scale of these are such that adding too many colors starts to make the whole thing look like noise and it gets hard to distinguish terrain shape (basically it starts to camouflage).