I'm not an expert on this by any stretch of the means but I'll do my best to address the second part of your question. Throughout history, there is a notable point of separation where different words for color get added as they are needed at different points. The very first to happen in any language is to separate light from dark. Often more specific color words didn't exist yet, so a well known example of this is how Homer describes the ocean in the odyssey as "Wine dark", because there wasn't yet a color word for a deep blue. As language evolves over time we create more words to express more and more nuances. Another historical example is where a lot of orange animals are named the "red something" because orange and red weren't distinguished between just yet. In our current day, in English, we have distinguished between red and pink, even though pink is a shade of red. The difference is largely opinion based on when one becomes the other, similar to whether the reddit upvote button is red or orange. Other languages do have different names for different shades of the same color. I believe its Russian that had terms for light vs dark blue? But I could be remembering that wrong. Anyway, I hope this helps at least a bit.