Easier seen than explained, so here are screenshots:
With Ambient Environment installed
Without

You may notice the Ancient Warfare structure there, but in another MC instance I found the same issue with only Ambient Environment, Project Vibrant Journeys, and Nature's Compass (to find a prairie quickly) installed.

Color value overflow? Not sure. Otherwise, loving the mod

same issue with biomes o' plenty Orchards

Should be fixed in latest versions :)