Well, if it is a 70w MH and not the 2 PC lights then disregard my lighting concerns. That is enough for the condy anemone in that vaulme of water.. now, size of the tank is the other concern. I just got rid of my condy anemone yesterday, after caring for it for over 5 years. It was taking up 1/3 of my 29G tank. The tentacles were touching the glass on the front and back of my tank it was that big. Condys are usually considered the "small" end of the anemones in size also, and I personally tend to think one can do well in a smaller tank/less light than most others, but I still think the min size tank for any anemone is at least 20 gallons, preferably 24G being the smallest size tank.
The OPs anemone is still a baby though so it has a little while before it outgrows the tank, but it will if it survives.
The brown, while I personally have never seen 'brown' on my condy, I have read that it is usually a good thing. Now my anemone was bleach white from day one, and never really got any color over the years, but it ate like a pig, grew pretty big, and stung me and anything else it could touch, so I don't always think the 'brown' is a good sign from my experience. Some anemones are white, and are not bleached.
My Condy as a baby 5+ years ago:
My Condy a couple weeks ago: