Simply put, fawn, black and black brindle are dominant colors. Formentino, blue and blue brindle are recessive (dilute) colors.
A dominant colored dog can be pure dominant and are called "Clear".
A dominant colored dog can also carry the recessive gene and are called "Carriers".
Dilute colored dogs are called "Affected".
A clear dog can only produce clear and /or carriers of the recessive gene, but not the dilute color. A carrier dog bred to an affected dog can produce both dominant and dilute colors. Cooper is a carrier and was bred to an affected (blue) female. Out of the thirteen they produced there were black, blue, formentino and one fawn.
It's believed by most experts (not all) that dilute dogs should not be bred together because of the increased likelihood of skin and immunity problems as well as other issues.