Silvera made guest appearances in numerous television series, mainly dramas and westerns, including Studio One in Hollywood, Alfred Hitchcock Presents, Bat Masterson, Thriller, Riverboat, The Travels of Jaimie McPheeters, The Untouchables, and Bonanza. In 1962 he portrayed Dr. Koslenko in The Twilight Zone episode "Person or Persons Unknown", opposite Richard Long. That year, he also played Minarii, a Polynesian man in the 1962 film Mutiny on the Bounty, again starring Marlon Brando. In 1963, Silvera was nominated for a Tony Award for Best Actor in a Play for playing Monsieur Duval in The Lady of the Camellias.