IMO, it makes no sense to speak about the colors of the landscapes without a skybox, because it is all about the balance between the colors of the view as a whole.
F.i. a skybox with a sun that gives the sky an orange touch would make the colors of the green absolutely fitting.
After choosing a skybox you could have to adjust all colors again.
IMO, it is to early to discuss the "fine-tuning" of the colors, you have to adjust them at the end of everything.