Originally posted by luckies4me
If her eyes are black/dark red then yes she is a fawn, however if her eyes are pink than she's an amber. It's hard to tell if she is a berkshire unless I see the markings. There are a few different markings with white on the belly. The English Irish which is white in between the two front feet, on the chest, which should be as close to a triangle as possible, pointing down. The American Irish has a white belly in the shape of an oval, but does not cover the inside of the legs of neck. The berkshire has an all white belly, covering to the sides and up the neck, and depending on what type of berkshire, either going up the legs, or stopping at the legs.
To go along with Cass' excellent explination, here is a rat breeder with good variety/color pictures you can check out Jynelle to get a good visual idea: CLICK HERE!!! You gotta scroll down to the bottom of the page.

p.s. CASS- QUIT POSTING THE SAME TIME AS ME!