Addendum

Artists traditionally limit their pallet because depending on the pigment used the colour will behave differently.

For instance, winsor yellow is transparent, cadmium yellow is opaque and bismuth yellow is in-between. Mixing transparent pigments yield vibrant secondaries and tertiaries but mixing opaques give mud.

You see, there are only so many minerals we can use to create colours and each one of them has their own properties. Do you know how long it took us to find alternative blue pigments? A hell of a long time!

There are tons of other factors too, like the consistency of the mixture and the permanence of the colour.

So artists would stick with the same pigments and learn them intimately and only expand their pallet slowly and carefully.

That's why it's noteworthy enough for literature when artist x switches from viridian green to cadmium green or when artist y picks up emerald green.

Some artists, like Turner, would make their own paint from scratch.

Of course, this is all becoming somewhat of a lost art these days, especially with the advent of digital paints, where your yellow behaves like yellow and your blue behaves like yellow.

But the more that you know, right?