The role marks the latest gig for the "Late Show" host as he's set to say goodbye to the CBS staple next month. Warning: This story contains spoilers. Stephen Colbert is lending his voice to the resistance in Hulu’s “ The Testaments ” before he bids farewell to “ The Late Show .” Colbert made a surprise voice cameo in the new series, a sequel to “ The Handmaid’s Tale ” based on the follow-up novel by Margaret Atwood that follows a new generation of women in the totalitarian society of Gilead.