Genetic Formula: Caused by a combination of other factors and modifiers, not yet a scientifically discernable gene.
Brown is not a genetic color see BAY or SOOTY for further explanation.
Preliminary testing by a laboratory in France indicates that the "Wild" variant of AGOUTI (A+) rather than Pangare may be the agent causing the Seal Brown pattern. Apparently, all Seal Browns so far have tested positive for Agouti.
The foal pictured above is genetically a Red base + Sooty
Below is silver dapple factor modifying a black base
Red + creme = Palomino + Sooty factor. Often called chocolate Palomino. Silver Dapple factor can also cause this look.
Black + Agouti = Bay + Sooty Factor Commonly called a seal brown.
To read more technical color descriptions please visit UC Davis