I like how you handled the scales, it adds lovely texture to her tail, especially in contrast with her skin I like the limited use of color as well, it makes the blue appear even richer.
I haven't worked with set palettes much, though recently I tried it out for a character I'm brewing (using a random palette generator), and it was quite fun, I tried combinations I wouldn't have on my own. Definitely will try it again later on!
Two-color palettes can be fun to work with sometimes. ^_^