"Snowclone" defined

A snowclone is a type of cliché and phrasal template originally defined as "a multi-use, customizable, instantly recognizable, time-worn, quoted or misquoted phrase or sentence that can be used in an entirely open array of different variants".

An example of a snowclone is "grey is the new black", a version of the template "X is the new Y".  X and Y may be replaced with different words or phrases – for example, "comedy is the new rock 'n' roll".  Both the generic formula and the new phrases produced from it are called "snowclones".
More information (and examples) at Wikipedia.