Both of these golds are highly transparent and dispersive, and both are made from nickel. Nickel Azo Yellow is more of a yellow – warm and ochreish in masstone and cool and lemony in dilute – while Rich Green Gold is more, well, green! It looks to me like pickles. Both make more muted, naturalistic greens with Phthalo Green than a bright yellow would.
For my money, they have roughly the same role, so which of these should I pick for my palette?
For all of these mixes, I used Mission Gold’s Green Gold (PY150) and Daniel Smith’s Rich Green Gold (PY129). Despite the similar names, MI Green Gold is actually Nickel Azo Yellow.
Quinacridone Magenta (PR122)
When it comes to magenta, the difference is striking. PY150 makes fairly bold golds and oranges, while PY129 makes more muted and brownish tones.
Phthalo Turquoise (PB16)
Blue-tinted greens. The PY150 ones are bluer and crisper while the PY129 ones are more muted and yellowy.
Phthalo Green Blue Shade (PG7)
Again, clean middle greens (similar to Hooker’s Green) from PY150. More muted, yellowy greens from PY129; these remind me more of Sap Green.
Neither of these make the most vivid mixes (as a Cadmium Yellow or similar would), but the mixes with PY150 are “cleaner” and more typical of yellow, and I find I generally prefer them. PY129 mixes more like a yellow than a green, to be sure, but its mixes all have an avocado cast that reminds me of the 1970s. It is probably best for autumnal mixes, but I didn’t like it as much as NAY for my autumn palette, since it doesn’t do golden hour sun rays as well. I couldn’t really find a situation where I prefer Rich Green Gold in a head-to-head, so for me, the winner of this one is Nickel Azo Yellow!