Colored gold alloys

Hi, everybody! I’m looking for a source of colored golds, other than
red,green,yellow & white. Or “recipes” for alloying them. Anyone
out there know of any. Also have found some references to Steven
Kretchmer and his fabulous purple and blue golds. Any of you know
of a way to caontact him? Thanks in advance for any responses! Frank

hello dear ganoksin members

i want to make my own alloy PURPLE color, BROWN and BLUE color
anybody know how many percent i should put 585 au+ ? ag + cu ?..
i want to make 14 and 18 carat
also i need how many temperature is is melting

thank you your helps
best regards