@Lee-White @xin-li Quinacridone Gold is a good example of how pigments with the same name can vary considerably across brands. Daniel Smith (and Winsor-Newton) had a single transparent pigment Quinacridone Gold (P049) until it was discontinued. I still have a tube and it’s my favorite for warm, transparent yellows and mixing warm greens.
Daniel Smith replaced it with a combination of a transparent orange (Quinacridone Orange, PO48) and transparent yellow (Nickel Azo Yellow, PY150), which I haven’t tried, but you will see watercolor artists complaining that they don’t like it as much as the original.
Winsor-Newton adds 2 transparent pigments to the Nickel Azo Yellow to make their current Quinacridone Gold, both in the red-violet family (Quinacridone Maroon, PR206 and Quinacridone Violet, PV19). I would guess that this brand is going to look duller with the addition of colors that border on being a complement to yellow.
Schminke’s adds a rust-color (Red Iron Oxide, PR101) that can be less transparent to the Nickel Azo Yellow.
Sennelier’s Quinacridone Gold is a cross between Winsor-Newton’s and Schminke’s, adding to the Nickel Azo Yellow the rust (Red Iron Oxide, PR101) and a red-violet (PR206, Quinacridone Violet).
You will find the pigment numbers in very small print on the side of tube watercolors (not sure if pan watercolors include that information). It can be very helpful to reference these numbers in getting to know the characteristics of your watercolors rather than doing so through trial and error. Not just transparency, but whether or not it’s a staining pigment, lightfastness, how granular it is, etc. This knowledge is practical: for example, if you think you want to lift color from an area, don’t use a staining pigment, but if you want to mix a rich intense black, use staining colors like Perylene Maroon (PR179) and Phthalo Green (PG7).
Knowing the formulations can also save you money when you find out that Daniel Smith’s “Opera Pink” that’s calling you is PR122, the same number of the Winsor-Newton tube of Quinacridone Magenta already in your collection of red watercolors