[finite_depth says this much better than me in a parallel comment!] I believe this is explicitly about how 'regular' speakers of languages agree on colours, an

[finite_depth says this much better than me in a parallel comment!] I believe this is explicitly about how 'regular' speakers of languages agree on colours, and which are distinct. For instance 'lime' can describe a colour - typically a light green. But most English speakers [citation needed] would consider it to be a shade a green, not a distinct colour. Similarly, looking at this small colour chart of Pantone shades: https://www.wardrobeoxygen.com/wp-content/uploads/2020/01/Pantone-Colors-Spring-Summer-2020.jpg https://www.wardrobeoxygen.com/wp-content/uploads/2020/01/Pa... - if asked unprompted you probably wouldn't call the shades "Flame Scarlet", "Saffron", and "Chive", but Red, Yellow and Green.