Hello A.R. Frost. I like the overall shape of your land mass, and the color palette you are working with (though a few more colors in just the right places might help to give your map more texture). I would recommend blending the the colors between your polar and temperate zones a bit more gradually, and perhaps adding a few waves or ripples within the ocean (particularly around the...continent/island?).
Cheers,
-Arsheesh