It works better in-game than as a standalone map: different styles for different purposes. As far as the contrast and saturated colors - that's aesthetics and thus your call. I'll just note from decades of staring at a CRT all day that I get less eyestrain and headaches from subdued colors and decent contrast than from bold ones or either low or mega contrast. I bet color is something you could tweak without recoding or messing with rules? Even barely a pixel of a dark outline on the land masses might help.

A game board is different from any individual map -- figure your users will be staring at it for hours for the former vs. minutes at a time for the latter. Even distribution of landmasses and filling a rectangle make plenty of sense as a game domain - I'm all the time starting to dispute layout on some Avalon Hill boardgame, and I have to remind myself Its A Game. Lots of pretty maps would make lousy games.

I say good work, with room for modest improvement.

And of course the question others here are thinking too - is this game available? ;-)