More visual differences on maps

Currently, most biomes display very similarly on maps. Apart from pale oaks and cherry blossoms, all trees show up as the same green color. The same goes for grass blocks. This means that oak-, birch- and spruce forests, jungles and savannahs (just to name a few) all look essentially the same. I think maps would be both more useful as well as visually interesting if there were differences in hue depending on the biome that is mapped out. These wouldn't need to be very drastic differences, just enough that one can tell where the borders between biomes go.