Can fancy guppys live in a 20 gallon tank?

I'm looking for some colorful fish for a 20 gallon tank I was looking at fancy guppy's but I just don't know if they could live in my tank with 3 bloodfin tetra 1 lemon tetra and 1 cory catfish and I only have flake food but could buy something else what are some good colorful fish for me?