I've been trying to get a Tinted Lens Butterfree for about 3 hours, but I haven't run into a single one.
The Safari that I'm using doesn't have a third slot yet. Would this be what is causing this? Or Is the RNG just not in the mood today?
Pokemon in the Friend Safari will not appear with their Hidden Abilities unless your friend has beaten the Elite Four, which is to say Hidden Abilities will not appear unless the third slot in the Friend Safari is filled.