This post is maybe a little off topic, but the view of linguistic relativism and specifically of Whorf (Sapir–Whorf hypothesis - linguistic relativism), as well as many 19th and 20th century philosophers, was that the Ancient Greeks must have viewed the world differently to us, or to put it bluntly, that all ancient peoples must have been colour blind. This then extends to the modern day, do Russian speakers view the world differently because of the separation of light and dark blue, are English (and most other language speakers) blind to the colour голубой as it's grouped together with 'blue'?

When the significance of синий and голубой have been studied an effect is seen, Russians are faster at differentiating between these shades of blue. When it's put this way and framed positively it's absolutely an alluring idea and one used to sell language books, learn Russian to literally see the world differently, but is it significant? Russians are about 125ms faster at differentiating between shades of light and dark blue because having a separate word to group them into does confer some advantage, but importantly English speakers are still just as capable of distinguishing those shades. This is also true even for languages that lack distinction between other colours, a particular language not having a separation between say blue and green doesn't mean that speakers of that language are any less capable of seeing a distinction between blue and green even if they refer to those two colours using just one word.

Another example of the issues of applying such findings to a world view would be Mandarin which represents the month before as 'above' and the next month as 'below', and studies do show that Mandarin speakers are faster at determining whether March comes before April after having been shown a picture with some verticality. When looking at these results through a Whorfian lens it'd be easy to make the claim that Mandarin speakers view time as vertically. More studies were done, Mandarin speakers were once again faster at guessing up was previous (compared to down for previous) by 170ms. Seems conclusive and further evidence that Mandarin speakers may view time as being vertical, however, the same study found that mandarin speakers were 230ms faster at guessing left as previous (compared to right for previous) and they were faster at doing this than they were doing it vertically. Also noteworthy was that they found English speakers were 300ms faster at guessing left for previous than compared to right, and in both cases of vertical/horizontal guessing English speakers were faster than Mandarin speakers (although English speakers preferred bottom as previous to top as previous).

This is where the issues of linguistic relativism pop up and why today it's generally heavily criticised and no longer considered valid by linguists, when applied to colours or time it appears relatively harmless but it's not always framed positively and that has been the case for as long as the theory existed. An example of a harmful application of it would be to look at the many African languages that use the same word for meat and animal, are they incapable of telling a difference between them? In English it's often pointed out that the term beef comes from the French aristocracy where the term cow comes from the Anglo-Saxon speaking peasant/serf class, which of these two would have been more acquainted with raising and slaughtering the animals and would they have been unable to make the differentiation? We absolutely know today that even despite lacking terms for certain colours people are still able to differentiate between them, to know this after having studied it and then say that the Ancient Greeks must have been colour blind seems absurd.

>So then what does it mean for languages who split blue into two colors?

Personally? It's really neat and being able to differentiate those shades faster is an interesting consequence of that, I just can't view it through a Whorfian lens. I'm also somewhat envious of the differentiation after having been told numerous times as a child that while teal/turquoise are blue they're not really 'blue'.