But Redmayne, honored Sunday at the 2010 Tony Awards as best featured actor in a play, says the role isn't as demanding as it might seem to the audience.
"I studied art history at university, and it's fascinating to me," he said backstage, "and the arguments are so powerfully written that it's actually much easier than perhaps it looks to get up and be passionate about it each night."
Performing in "Red" has also inspired him to take up painting again, he added, though he admitted, "I'm a really bad artist."
"Red," which won the Tony for best play, loomed large at the ceremony honoring Broadway's best, but the awards show was skewed in a musical direction: Its business was clearly show business.
"Welcome to the Tonys," said host Sean Hayes when it began — "the World Cup of show tunes."
He wasn't kidding.
The broadcast was packed with musical performances from nominated shows, including "Memphis," the rhythm 'n' blues musical set in the American South in the 1950s, which won four Tonys, including best musical.
Even the hit TV series "Glee" got on the bandwagon. Matthew Morrison did a full-scale rendition of "All I Need Is the Girl," from "Gypsy," followed by his "Glee" co-star Lea Michele belting out a Streisand-esque version of "Don't Rain on My Parade," from "Funny Girl."
Meanwhile, the nominated plays were disposed of with brief summaries voiced by members of their respective casts.
Hayes, who didn't win as lead actor in a musical for "Promises, Promises," did put on a memorable show of song, jokes and costumes, dressing up as everyone from Spiderman to Little Orphan Annie.
During his opening monologue he joked that his dual status as nominee and host "combines a good chance of losing with a good chance at bombing." He was only half right.
Hayes' "Promises, Promises" co-star, Katie Finneran, won the Tony for best featured actress in a musical.
Backstage, the wisecracking Finneran, who doesn't make her entrance in the Burt Bacharach-Hal David musical until after intermission, said she views the first act from an unusual vantage point in her second-floor dressing room.
"I can actually go into my toilet, open the trap door, and I am in the house," she said. "I can watch the show behind the curtain, right from my toilet. I call it my view from the loo."
Johansson won for best featured performance as an actress in a play for her Broadway debut, the object of her uncle's lust in Arthur Miller's "A View From a Bridge."
"Fela!" — the innovative Afro-beat biography of Nigerian superstar Fela Anikulapo-Kuti — and "La Cage aux Folles" — a revival of the classic Jerry Herman-Harvey Fierstein musical farce — each had 11 nominations, but won just three Tonys apiece.
Douglas Hodge, who won best actor in a musical for "La Cage aux Folles," said his Tony was "tremendous encouragement."
"It just feels like I can really get on with it now," he said backstage, "and dig deeper and deeper, and mean it more and more." The role of drag queen Albin/Zaza was the Broadway debut for Hodge, who won an Olivier Award for playing the part in London.
Levi Kreis, who with fellow cast members of "Million Dollar Quartet" — about a fictional jam session of Johnny Cash, Elvis Presley, Jerry Lee Lewis and Carl Perkins — helped kick off the broadcast with a stomping "Blue Suede Shoes," won the Tony for best featured actor in a musical.
Asked afterward if his prize would affect his performance as rock 'n' roll wild man Jerry Lee Lewis, he said, "I hope not. I think the authenticity and purity of a performance has nothing to do with approval."
The goal of every performer, he said, is "to get to a point where what comes out of them never has anything to do with that, but always comes from an authentic place. At least, that's my goal."