What colors are my gerbils?

Hi! I just recently got two gerbils as a class pet for my middle schoolers. They are both female and I was curious on if anyone knew the technical names of their colors. I know there are a bunch of different colors they can come in. My students keep calling them white and black when they clearly look grey and brown to me, but I was looking into it and one may be Agouti? Please let me know, thanks!