Why hunter green? Personally, I wouldn’t color drench my bathroom in hunter green.

I just love a dark green with champagne gold but also feel I need to add color somewhere

Find a more colorful runner and buy matching towels. A random dark green wall will look odd.
If you use this bathroom for your morning hair and makeup routine, a neutral light colored paint and excellent lighting are the most important elements.

I like a dark green to but think color drenching in dark green will be very overwhelming and suck up all of your light.

Consider doing a small wall of it and a fresh bright white. You could do mirrors in the alcove shelf or maybe the same wallpaper as behind the toilet. Could even be a coordinating wallpaper in a more subtle print.