I’ve read in the past that the technology is there for tyres to be any colour the manufacturers want them to be (and not just by painting them, actually colouring the rubber), but they’re kept black because they are traditionally black, stemming from when the technology wasn’t there to make them any colour, and they had to be black.
I think the coloured writing works well enough, far better than the green ring. Be good to have some colour back on the tyres after years of Bridgestone and Michelin white.