Wow, what a terrible misunderstanding of colour.

Competing explanations that make as much sense and avoid the need for retarded ideas around recent evolution:
The reason old paintings lack certain pigments is entirely practical i.e availability and or price. Such practical reasons occasionally crystallize into art traditions, even when no longer applicable. The reason old languages rarely used names for colours is because they were less abstract, meaning homer did not say sea was the colour of wine. He said the sea looked like wine. In older translations the emperor garments are as rich ripe plum, not imperial purple. Not that colour or pigment was unknown, it just wasn't used in common speech as it was essentially a technical term mostly used by artists.

Colour looks more like an artifact of language, its accuracy limited by language, rather than a low level visual feature, and as such people are both terrible at communicating what we know. As a result people are terrible at colours, but really only at communicating our understanding of colours, not actually at seeing colours.

This kind of stupidity regarding colour seems to be multiplying, so let me just point to a single experiment you can do yourself to rapidly disabuse yourself of the notion that our perception of colour is distinct from our ability to express colours by name lingually.

Create a simple game where different nuances of colour at the same brightness (use hsv to generate) are shown next to each other. In rgb the difference should be 4 out of 255 levels for one of r,g,b. You receive xp and a pleasing sound whenever you guess correctly proportional to how fast you chose, and you recieve hp damage and a nasty sound and whenever you are wrong, or take longer than 1 second. connect left mouse to the mark the left image, and the right mouse to the right image. Play for an hour or two. You will get better quite quickly. This disproves the idea that we cannot se colours we dont have names for. Further, at least for me, even before doing this I could tell the difference between far more nuances than there are names for colors in a simple grid of hex coded colors. I even remembered where the nuance I wanted was in the grid. Similarly, propose to replace the color pickers modern cg artists use with a dropdown menu of only the colors that there are names for and note how pissy they get.

The same brightness is unfortunately important because both modern screens, modern cameras and artists description of colour fail to account for the simple fact that we have 4 different receptors, not three, and the fourth massively changes how we perceive colours (ever noticed how cameras make everything look redder in low light, unlike your eyes beholding the same scene?). So this compensates for that. Similarly 4 intensity levels aren't the limit of our accuracy, its just the limit of typical modern screens. If you have a high quality ips screen, and haven't messed with the color projection too much, you can lower it further.

There is no scientific consensus on colour, mostly because its ill defined, but we do know definitively what it is not, and the ideas presented in the article are just wrong.