If you’re talking about stying the ACF field and the selections/labels based on the value and not anything to do with the front end theme, well, that’s not really something that can be build into ACF. You’re talking about styling each selection based on the value of that selection. The current ACF UI for these selection fields is a textarea where you enter value/label pairs. The UI would need to be completely altered to give you a way to enter each value separately with its associated label and any special css classes and id attributes for each value. That would be more than an minor change I think.
If you’re talking about on the front end, here you are on your own, but I would suggest going back up and reading @giovannicold’s reply.
