> I don't have some `colors.scss` with a bunch of constants, and then redefine those same constants in my .js anywhere -- I have a .js file with my palette.

Thank you for your reply. Do you have an example repo of using this pattern? I'm afraid I'm not terribly familiar with _not_ having any css files and instead defining it in a js file. create-react-app maintained by facebook doesn't seem to follow this pattern (unless I'm misunderstanding).