BLACK
Black, or aa, is a single gene color. It is one of the genes that silvers. It is a reccesive gene, meaning that a hamster has to have two of these genes to appear black. But, the black gene can be carried and not show up at all.
ARGENTE ( RED EYED )
Argente (pp) is a rust-like colored single gene. Among the two types of argente (RE & BE), the one with red eyes is considered "argente" and the one with black eyes is considered "black-eyed argente". But to clear up confusion, most people say RE (red eyed) and BE (black eyed) argente. Argente is a reccesive gene and does not silver.
ALBINO
The albino gene is a unique color. Albino, or cc, is a single gene and is reccesive. The hamster appears completely white with red eyes. Albino is so unique because it covers up all of the other genes it carries. Therefore if a hamster has 2 black genes, 2 normal genes, and 2 albino genes, the albino shows up. Every time it covers the other genes. That is why there are no combined albino colors.
OPAL
Opal (dd) is a single gene. It is reccesive, so it needs 2 opal genes to appear opal. Being reccesive, though, means that it could be carried and not show at all.