The caption for this clothing in Chuck's Locker reads "Orange is the new black".
"_____ is the new black" is a catch phrase used to indicate the sudden popularity or versatility of an idea at the expense of the popularity of a second idea. It is the originator of the phrasal template "X is the new Y". The phrase seemed to have started in the 1950s or 1960s and became very popular in the 1980s. Since then it has often been used for ironic or humorous purposes.