Glad you enjoyed it! Okay, so based on my understanding of Deutscher's theory, the ancient Greeks could visually distinguish between what we moderns regard as blue and red just as much as we can -- it's just that they didn't consider them as distinct colours, but rather different shades of a single colour, red. So whilst ancient Greek fresco paintings might appear to us as being painted in blue, green and yellow, in their eyes they would appear as 'red', green and yellow. In a similar way, if you look at Pantone PMS 326, you might say that it's a shade of blue or green, as those are the closest colour descriptions that we could muster, but to Pantone colour experts, such descriptions would seem rather crude and imprecise. Whilst we can visually distinguish PMS 326 from more, shall we say, prototypical shades of blue or green, we simply lack the vocabulary to describe it without referring in some way to blue and green. We just don't have a unique word for all 10 million colours that are visible to the human eye, and so we're forced to describe 10 million colours in reference to 7-8 colours, which is incredibly reductive. And so whilst we could paint a house in the colour of PMS 326, if asked to describe the colour of our house we might simply describe it as 'green', 'blue' or 'aqua'. But just because we don't have a word for PMS 326 beyond this rather technical name, it doesn't mean that we can't distinguish this hue from, say, indigo. We know that it's "a different blue" from indigo, but we may still refer to it as "blue". In a similar way, the ancient Greeks could see that a sky on a sunny day was not the same hue as a sky at sunset, but since they lacked a word for 'blue', they would have described an azure blue sky as 'red', albeit a different red from red wine. I hope that makes sense! Don't know if I'm being clear.