Article continues below advertisementDuring an emotional appearance on The Late Show on Tuesday, April 7, Oprah Winfrey surprised host Stephen Colbert by taking his seat to conduct a "role reversal" exit interview as his tenure nears its end.Winfrey moved from the interviewee chair to the host's desk, asking Colbert personal questions about the show's upcoming conclusion on May 21.She asked Colbert what he felt ready to "release" before he goes. Colbert responded emotionally, saying he still had a "white-knuckle grip" on the people he loves and works with.