yellow catt leaves

[weederwoman]

I have a NOID catt ( small bifoliate) whose leaves have all turned quite yellow since I put it under lights for the winter. It is mounted so I can tell that the roots are still fine. I'm guessing its too close to the lights, but my other catts get purple on the leaves when that happens, not yellow. It gets the same care as all my other mounted catts, none of which have this problem. I will lower it, but any other ideas if light levels are not the problem? It just bloomed for the first time since I was given it, by the way.
White. Thanks

[dounoharm]

I have noticed that red or pink cats leaves turn rather red with too much sun, but others do get pale green, a little yellowed looking when they get too much sun....so yes, lowering it from the lights is a start...can you post a pic of it? does it have any other problem that might be the cause of this? how do the psuedobulbs look?

[weederwoman]

Will post more info tomorrow. I'm assuming the leaves will remain yellow even after any corrections.
Thanks
Later post
I've been doing a lot of reading on the web, and it seems that yellow leaves are a common sign of too much light, as I suspected. But so are red/purple tinged leaves. Depends on the breeding or the color of the flower or both, no doubt. Would be an interesting experiment for someone who likes to torture orchids.

[WeirdGuySeattle]

is it just a few leaves, or whole plant? If its just a few, you might up the fertilizer you give the thing. Sometimes mounted plants don't get much nutrition if its not getting the benefits of your potting bark breaking down - rainwater gives some nutrition, but tap water might not as much.

yellow leaves can be a sign of not enough nitrogen. But if its whole plant, you might look for other problems (rot / water / light)

[weederwoman]

Its the whole plant. I've been using a non urea fertilizer on my mounts to help with nitrogen utilization. I think it is also an especially fussy plant. The man who gave it to me wasn't having any luck with it in his home and thought it would do better in my greenhouse environment. His wife's father raised orchids in Hawaii, so they weren't total newbies. It has really improved the last two years and grown well till now. Will the present leaves always be yellow if too much light is the only problem? How much will this harm the leaves ability to nourish the plant? Thanks