Your nem should be a creamy beige/brown color, when it starts regaining zoox. you'll see the color start to change. Ours was very faint at first, but became more noticable shortly after that.
Did you already tell us how old your lights are? If not, will you please?
I remember you saying it doesn't like the light, and I wonder if it's a little strong for it in such a bleached condition. Some have wondered if the zoox. acts as a sunscreen of sorts. It may also have been under low light before you got it and had trouble acclimating to more intense light. I wonder if adding screens to help diffuse the light would allow it to acclimate to you lighting. I think the idea is to layer screens and remove one each week or so so that the lighting is gradually increased.
I have no idea if this idea will work, so I would wait for more info and ideas. It's just a thought.
Good luck!