* Vladimir and Estragon in ''WaitingForGodot''
* In ''RosencrantzAndGuildensternAreDead'', Rosencrantz is red and Guildenstern is blue.
* ''{{Hamlet}}'' (red) and Horatio (blue), conforming to the ZerothLawOfTropeExamples.
* In the movie version of the [[Theatre/JekyllAndHyde musical Jekyll and Hyde]] (yes, the one with [[GermansLoveDavidHasselhoff David Hasselhoff]]), Dr. Jekyll is shown with a [[http://s233.photobucket.com/albums/ee306/Loracarol/?action=view¤t=Jekyll.jpg red light]] (hard to tell in this picture, sorry) and Hyde is shown with a blue light shining on [[http://s233.photobucket.com/albums/ee306/Loracarol/?action=view¤t=Hyde.jpg him]]
* ''RomeoAndJuliet'' gives us Romeo (red) and Benvolio (blue), Mercutio (red) and Benvolio (blue), and even Romeo (red) and Juliet (blue).
* ''Theatre/TheLadyFromTheSea'' by Creator/HenrikIbsen has the Wangel sisters: Hilde (red), and Bolette (blue).
* To a degree, Henry Higgins (red) and Colonel Pickering (blue) from ''Theatre/{{Pygmalion}}'' and ''MyFairLady''.
* ''AGentlemansGuideToLoveAndMurder'': Sibella and Phoebe to a tee. They even wear giant pink and turquoise dresses, respectively.