There is also a Brochis splendens which is often called an emerald green cory. It's not a cory, however. It's a brochis which looks like a cory, but is bigger than a cory.
There is actually a green cory, which is rarely seen, but since you are asking about it being dyed, I'll show it to you. It is not dyed; it's natural. This fish is a color variation of the C. aeneus. It looks like it has a neon tube buried in its body and is absolutely gorgeous. It's probably number one on my want list. I have similar ones that are gold. It is the only fish I ever ordered by mail and I was not disappointed.