Delete old labels from Epic / Roadmap views

I need to delete a bunch of old labels that appear in the Roadmap/Epic view when assigning a label but none of them appear when I am in the ticket view. It seems Epic labels are created from the ticket labels in Github, but when you delete the Github label, it does not delete the label in the Epic view. We’ve gone through a lot of re-labeling and I can’t seem to get rid of ALL the old ones.