The two accepted colors for Dalmatians are black and white and liver and white. These are caused by a simple dominant vs. recessive gene. Black always masks liver. Two (black) dogs with the same phenotype (they look the same) can carry different genes.

It is noted as BB for a dog that can not pass on anything but black, and Bb for a dog that is capible of passing either a liver gene or a black gene. In dals it is usually called liver factored.
Liver is recessive and the dog must not carry and black genes in order for it to show.


Other recorded colors are lemon, orange, blue, brindle, and tricolor.
I know that blue is caused by a dilution of black and tricolor has to do with masking. Here is a website that covers the genetics better than I can:
http://geocities.com/~paisleydals/color.html
Lemon:



Blue:


Brindle:


Tricolor:
www.geocities.com/paisleydals/color2.html