In dogs,eumelanin consists of molecules of DHI and DHICA. DHI and DHICA are made from dopachrome. DHI through DHI oxidase and DHICA through DHICA oxidase also known as TYRP1. When TYRP1 has a mutation through which it loses its function, mostly DHI is produced which gives brown eumelanin. Now, if TYRP1 is functional, are both DHI and DHICA produced? If no, why not? If yes, why does the eumelanin appear black and not a dark brown?