That's actually pretty good looking coral. The only thing I'd do is maybe reduce the opacity on it, make it a bit more subtle. My only other nitpick is that there seems like there's too much contrast between the color of the coastline and the color of the mountain/tree outlines. Maybe pick a color halfway in between the red-brown of the coast and the black of the mt/tree icons and use it for both? Black would be too harsh to use as the coast outline color, so I think you're on the right track using something more subtle there. Awesome work so far though; I like the dual legend/key boxes along the side. Have some rep for sharing your first maps here!