Neon green didn't lose color in low light in my tank, only slow growth.
The pale one, whitish-brownish with hint of cold green if contracted, likes good light and grow fast, but I never seen them having better color, always drab.
Bi-color, green center, brown perimeter, thick skeleton - likes light too, and I suspect, that prefers the cleaner water.
On another hand, the bleaching could be caused by too much light, or by stress, if there are aggressive corals around.
Just a thought.