Bottom: Daniel Smith – Rich Green Gold (PY129).
Both of these golds are metal complex azomethine yellows: PY150 made from nickel, and PY129 made from copper. Both are highly transparent, smooth, and dispersive. They differ in hue; Nickel Azo Yellow (PY150) is more of a yellow – warm and ochreish in masstone and cool and lemony in dilute – while Rich Green Gold (PY129) is more, well, green! It looks to me like pickle brine. Both make glowing yet subtle, naturalistic greens with Phthalo greens/blues.
They have the same role as green mixers, so which of these should I pick for my palette?