James
genetically all dogs are either black or liver..its the dilutions and expressions of genes that detemtrine the actuial coat color..
but when genetecist refer to genes,every dog will either have a black or liver assignement.
we had a long discussion on this sometime ago..I cant remeber the thread, but it is in the archives somewhere..
a standard color can have the b gene, but the color will not be expressed.such as Bb etc.