Regular expressions make you queasy? Here’s an approach with less hairy regex syntax:
1. Run the search:
/background-color
2. Start a recording:
3. Make the edit, exit insert mode and jump to the next match:
Wct;black<Esc>n
4. End the recording:
q
5. Run the macro a bunch of times to replace all matches
999@q
https://mastodon.social/@normalmode/112654391888897023
Yes, running it 999 times is a bit crude: there’re more precise ways to do this, but they’re (slightly) more complicated to explain.