Looks like an ebony to me . You should also do away with that house. They are clearly chewing it and plastic isn't good for them. I'd find a wooden one.
This isn't actually mine. I am trying to get my colors right and I couldn't identify this one. I have wooden ones myself. The owner/breeder is saying this is an extra dark ebony. the father is an extra dark/**** ebony. The mom is a pink white.