If its not enought light...test this by moving the plant as close to a window that gets bright indirect light and see if the color starts to return. Dont put in in direct sun until it acclimates. The other reason for green is to much fertilizer but since its winter that souldn't be an issue.

Thanks Hotdiggetydam,

Here's a picture of the plant. I had it under a light most of the winter and recently (about a month) stuck it in this window. The light was nothing more than a lamp with CFL light bulb. I have not fertilized since the fall. But, I have no idea how or what I should be using. If you don't mind can take a look at the picture, I have noticed some marks on the leaves that can be seen in the pic. They look as if you could wash them off but have 0 texture to them and seem to be discoloration in the leaves themselves. Again thanks for the response and any tips you could offer to help out are really appreciated.

John

Think of the brown colour as a sun-tan . You pale up over winter as does your ortho ;-)
Don't forget to use a sunscreen .