If you bought 4 red rcs, then you got all females. Only the females are red.
To begin a breeding program, you're going to want to buy closer to 20-30.
I can sell you 20 for $30 shipped. Interested?
I take paypal. PM me. :)
The only trick to breeding them is to make sure the only filter in the tank is a sponge filter. That way they won't get sucked in.
If you want to breed shrimp, I would breed RCS and Crystal Red shrimp. They fetch a premium and are easy to breed.
As far as food, I feed:
blanched carrots, spinach, and zuchinni
raw pumpkin (fresh not canned)
fish food flake, crushed (in small amounts)