Welcome to the "Elder Crags" tile set.
After receiving lots of critique on the old version, I started a thread in Pixelation dedicated to improving the mockup in all aspects. You can read about the progress, step-by-step, at this link:
I believe each element is 16 colors or fewer, with no recycling between elements. From a game development angle, there'd be no reason to pursue palette unity, especially since my goal was to make the graphics more slick than retro.