How long does it take for a rbta to recover its color and size?

[FishAreFriends2]

I got one a while ago and it was red and big but now its losing its red because of my water quality but I am working on it. So I am wondering how long will it take for it to gain all of its color back? It also shrunk in size.

 

[dc]

Are you feeding it well also? I would think it can recover fairly quickly by the pictures I've seen here. Depends on your care.