I’ve spoken repeatedly of the primary colors in Premo. Are there primary colors in other brands of polymer clay? Yes, there are! But note that some brands of clay DO NOT have good mixing primaries.
As a quick review, what do I mean by a “mixing primary”? I just mean that they have colors that are as close as possible to a clear cyan, yellow, and magenta as possible without carrying other colors. AND that the colors don’t also include white or black (which will further muddy the colors). Remember that the hidden colors can often shout loudly when you start mixing colors. (The photos are test tiles I use for testing products on various brands of clay. The colors are made from the mixing primaries of each brand, when they have them. Note how Souffle and Sculpey III aren’t clear, true colors like the rest.)
Kato has great mixing primaries. Kato has a limited range of colors, in what they call “spectral” colors. The closest colors to mixing primaries are Turquoise, Yellow, and Magenta.
Fimo has a “True Colors” range which are single-color, pure pigments without added white or black. Fimo provides and extensive mixing chart to be used with the True Colors system. But this does include fairly true mixing primaries. True Blue, True Yellow, and True Magenta will get you pretty close. Be aware that the base of Fimo colors has a white color to it, which means that all Fimo colors carry along a bit of white into their mix.
The Number One line of Cernit does not currently have true mixing primaries. The Opaline line, which is half translucent, does have Primary Blue, Magenta, and Primary Yellow.
Souffle and Sculpey III
These lines of clay do not have true mixing primaries. While you can still mix amazing colors, you can’t use the “just three primaries” strategy to mix all the colors. All colors of both Souffle or Sculpey III are color mixtures, not single pigment colors.