What happens when fluorine is exposed to damp blue litmus paper?

When chlorine comes in contact with litmus paper it bleaches it, so it turns white. Before it turns white, though, it can turn pink because of the acids formed when chlorine reacts with water. Cl2 + H2O -> HOCl + HCl

Not sure about the effect of other halogens on damp, blue litmus paper, but I suspect that similar reactions would occur.