Dark Green/Red leaves on Phal

[RosieC]

First of all thanks to everyone who gave advice a few weeks ago when one of my Phal's dried out while I was away.

The good news is that there is both a new arial root which has appeared since then (and two existing arial roots have started growing again), and this morning I noticed the very tip of a brand new leaf appearing.

But I am still worried about it for a couple of reasons...

First, it's leaves are very dark green/red. It is in the same window as my other two Phals and they are a brighter green. (They get morning sun, then the sun moves to the side where there are no windows, then in the afternoon/evening the sun shines through a window oposite and 5m away.)

Could this be linked to the fact it got really dry (dry enough to loose half it's leaves)?

Could it be short of nutrients? I read that nitrogen is required for photosynthesis and I have not been fertelising this one while it was recovering. I was thinking of fertelising it this weekend when I do the others, is that a good idea or not?

Is this something I should be worried about, is there something I should be doing?

Secondly, since it lost the lower leaves it wobbles a bit. I can still pick up the plant at the base and the pot stays on (which I know is a test for whether it has been potted tightly enough).

I am worried that there is a problem with the roots in the pot and this is why it is wobbling (and also why it dried out so easily, although it is in new bark which is drying quickly). I can't see any roots through the clear pot or on the surface, but then I've not been able to see any ever since it was re-potted in April. I can see three long arial roots, two of which are growing new tips, and a new arial root is starting to grow, but I have no idea what the roots in the pot are like (I last saw then in April when I re-potted at which time there were lots and they were healthy).

Should I remove it from the pot and take a look?
I'm worried about disturbing it when it's still recovering but I'm also worried that the roots may be in trouble.