I'm not a rat guy by any means. Just know about the Dumbos from pet stores. They make great pets, and grow big like an XXL/Jumbo normal. They bring more money than than Normal jumbos.
Yours look like a Dumbo from this layman's eyes.
Being ignorant about rats, I call it a white and grey or a Blue and white.
To get accurate information go over to the rat breeding section on this site and ask those guys. They can answer all of your questions. :)