Variables are hugely helpful, I agreee.
IDK about bikeshedding. I'm very used to writing React code that normally declares no styles for components at all, and having CSS that style components using 1-2 classes, specific to these components. Container components control margins, <body> controls general things like fonts.
replyIt seems that what solves the problem is a good component library. "But I need red text here!" For what reason? It's a warning. OK, we've got <Text variant="warning">, it will be styled appropriately, and will look like every other warning in the application.