(Excellent size comparison of full grown dwarf and full grown standard)

I had a dwarf rat pop up in one of my 2013 litters. You will be able to tell a dwarf from a runt as they age instead of when they are born. The dwarf when full grown is about the size of a rat that is a little over a month old. The color looks like a platinum to me but I would have to know the colors of the parents for a better analysis. (You get platinum with blue x (ruby-eyed) mink)

I had a downunder that came out of feeder stock too, so random things do happen.