The eternal quest for the deepest colors in yellow gold…
I think Hauser and Miller makes the richest 18K gold alloy, but it’s
a little hard to torch melt (porosity/sparking issue), you’d be
better off using resistance or induction melting. I haven’t tried
their 14k, but it’s probably just as good.
AAA Precious Metals in Portland, OR makes a wonderful 14K alloy,
very rich. I think they’re just using cu,ag,zn in the alloy and you
could probably do the same with a bit of experimentation. Just the
same, their (I think) #34 alloy is the cat’s meow, the bee’s knees…
If you run across the ideal alloy recipe, maybe you’ll share it.
Best of luck