I have two fresh water fish they are both the same, one is lighter than the other, they are about 5" long. I also would like to know their sex so I can name them accordingly :)

I forgot to mention they have a black kind of dotted stripe on each side.

You would have to post pictures I think for someone to make a viable even educated guess at that.. your description is kindof vague

There are thousands of domestic fish breeds out there. If you could provide a picture, preferably a side view and another one near the anal fin, I can identify and sex them for you.