A few losses is acceptable. Usually thats the cas whenever I but shrimp. if you rul eout all the mention above posts, then youshould be fine. Some of their colors change due to their surroundings, enviroment, age, and of course during breeding. I would not worry about that. As for the red one I would remove/seperate that one fast. My colony of yellows never had a reddish or brownish one. The closest it gets to being another color is the snowball. It could be where you got the shrimps got mixed with rcs.