Create formatting for list column headers

Hello,

Using Classic UI, I would like specific column headers to be a certain color. For example: all columns headers that pertain to domestic markets are blue, all international are red. I can manually define which headers need which color.

This will hopefully make things stand out a bit while someone is doing Quick Edit.

I already have a stickyheaders script as well as a content editor to manually resize a column. My formatting experience is just due to googling, so the simpler the explanation the better. Thanks!