I can tell just by looking at the coastline where you've added the new sea in the south, because the coast has been left smooth as created, while the older coastline has been given random detail. The brightness of the green border between the dark southern lands and the light green midlands bothers me. It is so bright against the rest of the map that it seems specially significant, as if marking a magical barrier or something, whereas I assume it is merely a transition between the two colorings. Maybe it's just me.