Yes it is cultural, but it's complicated. There are some aspects of colour that are cultural, but there are also biological asymmetries so to speak, we don't ac

Yes it is cultural, but it's complicated. There are some aspects of colour that are cultural, but there are also biological asymmetries so to speak, we don't actually distinguish red/green/blue equally well, the colour receptors we have are more like red-yellow/yellow-green/blue for example. It's also something of a linguistic constant that red is most basic "chromatic" colour to distinguish, after making the the distinction between white and black. Perhaps because blood is red? The science of colour and colour perception is an incredibly fascinating subject, that even Goethe had a hand in shaping. I really recommend you to read at least https://en.wikipedia.org/wiki/Color_vision https://en.wikipedia.org/wiki/Color_vision