“The colours, man. The colours.”
Happy Potter is the name of a club in Stoke, positioned just across the road from the Miserable Painter club and right next door to the Little Chef.
Despite the name, it has nothing to do with pottery whatsoever, but exists simply to poke fun at the spirit of postmodern irony, ironically in said spirit of postmodern irony. Postmodern steely is made in Sheffield, but that's against the point.
In short, do not join the Happy Potters club if you value your lungs or brain cells.