PvP has been around since May 4, 1998. Scott Kurtz's strip had one major change when he redesigned the characters but otherwise the art style has evolved incrementally. Although Kurtz does drop in color from time to time the bulk of the comic is black and white.
First PvP from 1998 featuring characters Francis and Robbie
PvP from 2006 featuring characters Robbie and Jase
Recent PvP featuring characters Francis, Cole and Marcie.