I hear it all the time in reviews or discussions of tech products. I don't think it really means anything other than "color" or "color scheme", it's just a more product focused way of talking about it.
I am not a native English speaker, but isn't "color" more ambiguous than "colorway"? If I say "The red color is gorgeous", I could or could not be talking about a product. If I say "The red colorway is gorgeous", I am definitely talking about the color of a product.
"Colourway" is just marketing-speak that is not common outside of tech reviewers.
This needs a big dose of YMMV, I think. I've heard the term way more outside of tech, especially for footwear and in skateboarding.