Black partyhats are believed by some players to have existed for a short period of time in the early days of RuneScape Classic. It is accepted by most players; however, that this is a myth. According to this myth, black party hats no longer exist because Jagex declared them "not festive enough," so they changed the existing ones to white or purple partyhats. A variant of this story suggests that few people were able to obtain these black party hats, so Jagex decided to turn the existing black ones into white or purple ones. However, despite all rumors, black party hats do not, and have never, existed.
Through various gathering of information, the myth probably started from people having red partyhats, then changing their computer's brightness down. This made the red party hat appear to be black. How the rumors grew and spread as much as it has, was probably from misunderstandings.