The paint was splashed on one of the white columns supporting the Old Well roof. It was repainted white at about 8 a.m.
The vandalism took place on the eve of UNC-Chapel Hill's ACC basketball showdown with N.C. State. The Heels play the Wolfpack at 7 tonight at the RBC Center in Raleigh.
Graffiti chalked on the brick sidewalk surrounding the landmark were also removed.
"All we've got is very limited information," said Department of Public Safety spokesman Randy Young. "There was a cup [with red paint residue] that was left on the scene."
The incident reminded Young of a similar act that occurred before the North Carolina/N.C. State game in 2005. In that incident, Young said he thinks police caught the vandals in the act of stenciling an N.C. State logo onto the bricks.
A member of Wolfpack Nation released a statement saying, "So. Mr. Roy Fella, wudja think about that, huh?"