Buffy: Back off, Pink Ranger.
This is a reference to the favorite kids show Power Rangers, which has teenage superheroes fighting monsters. Pink is the one color in the shows history worn only by Ranger girls. This is a good in-joke for both Buffy and Power Rangers fans. James Marsters (Spike) dated Alison MacInnis, who would go on to play the Pink Ranger on Power Rangers: Lightspeed Rescue. In addition, Buffy's stunt double, Sophia Crawford, was also the stunt double for the Pink Ranger.