I thought the same thing about the swamps, I'm trying to add some "blue-ish-ness" to it somehow. I used the same exact layer styles for the forest and swamps except some more blue color in various places. I'm still experimenting on them, maybe incorporate some filters instead of styles. What I'm trying to get is something that has little blue squiggles surrounded by a dark greenish blue, but at the same time still be able to see that river flowing through it, without either being too bright or too muddled.