The text gives less obvious encouragement to reading symbolic significance into Mulligan's "yellow dressinggown" than it does with mirrors and razors, but in Christian countries this color had long been associated with heresy and treachery. In Circe these associations settle on Bloom.

JH 2011

The Arrest of Christ (Kiss of Judas), a mural by Giotto in the Scrovegni Chapel, Padua, ca. 1305. Source: Wikimedia Commons.

René Weis, The Yellow Cross: The Story of the Last Cathars (2001).