Have you ever wondered why we have a separate name for light red -- pink -- but no commonly used separate names for other light colours? Baby blue is as different from navy as pink is from red, but we can only identify it by adding a modifier to "blue"; it doesn't get its own word. "Pretty in Pink" makes a nice title, but "Pretty in Light Red" would never do. The same goes for light green, light purple, and other colours -- yellow, too, I suppose, although it's hard to think of yellow as being anything other than light. One could speculate that we use pink in a lot of common contexts -- flowers, lips, sometimes even skin colour, and it is the archetypal colour for girls -- but I don't know if that is adequate.
I've also wondered why green seems so different from the colours that form it. When I see purple, it looks red and blue to me; when I see orange, it looks red and yellow. But when I see green, it doesn't look at all blue or yellow; it looks effectively like another primary colour. I know this isn't just a cultural artefact, because I remember learning colour combinations and finding purple and orange perfectly logical, but green almost magical. Is it just me, or do other people see it this way? Just this evening I stumbled onto a reference indicating that many cultures do not even distinguish green and blue as colours,which is hard for me to understand. Interestingly, some of them do have a separate word for light blue, which makes perfect sense.
My son Jonathan and I recently ate lunch at Steak and Shake. He read a flyer that advertised "4 meals for under $4," and noticed that all of the meals were $3.99. It offended him, since they were only a penny less than $4; they shouldn't count as "under $4," in his opinion.