There is an interesting example of this in Robert J. Sawyer's The Neanderthal Parallax, which has an alternate world where the Neanderthals became the dominant

There is an interesting example of this in Robert J. Sawyer's The Neanderthal Parallax, which has an alternate world where the Neanderthals became the dominant human species. In the Neanderthal world, red means "good" or "go" and green means "danger" or "stop". This is because red is the color of good meat and green is the color of bad meat. In a remarkable HN coincidence, I was trying to remember the name of this series when I ran across kleer001's comment on "At Home with Our Ancient Cousins, the Neanderthals", also on the HN home page right now: https://news.ycombinator.com/item?id=26381829 https://news.ycombinator.com/item?id=26381829