If you haven't been to this site you might go to the home page and bookmark it.

http://www.afrma.org/ratgenwhatif.htm

So many of the rat traits are recessive which makes finding out what they carry much more difficult obviously.
I have 4 main color types I do and 4 coat types.
I have black, blue, Himalayan and agouti and hopefully agouti blues in my 2 current litters
I make standard coats, satin coats, rex and velveteen coats.
I also make blue black and Himalayan dwarfs and hopefully agouti dwarf's soon too.

It's pretty awesome to have a black rat throw nothing but Blue and Himalayan babies