Shades green gold alloy

Hi,

I was wondering if anyone has a recommendation on a nice rich green
gold alloy. I do a lot of 14K green gold casting and would like the
gold to have a richer green color than i am getting. I do realize
that 14K is a lighter shade than 18K but do different alloys produce
darker/lighter shades. Any recommendations would be greatly
appreciated.

Thanks,
hb