I bought this Santa Teresa from Four Winds last spring. When it arrived it had very yellow leaves, but I figured it would green up after repotting and getting it back out in the sun. Well, it's been months and it hasn't done a thing. No new growth, and it's still yellow.

It actually has developed some very faint green on the leaves if I look closely

Is there anything I can do to get it to green up and grow? It's in a 5-1-1 mix.

My large Shiranui is slightly yellowish, but getting greener since I fed it. My other citrus (New Zealand Lemonade, Vaniglia Sanguigno, a couple of kumquats) are green and growin well.

I've been fertilizing with Osmocote and Foliage Pro.