Referring to her own outfit, Blanchett later noted, "He would look great in nude and red."
To which DeGeneres cracked, "He would look great nude."
The Thor: Ragnarok actress also talked about her home life with husband Andrew Upton and their four kids -- Ignatius, Dashiell, Roman and Edith.
"We've moved to the country, so we got pigs and chickens and dogs and cats," she shared. "Our cat was raised by our Labrador, so it actually goes for a walk. Like, it walks the kids to school. It's really sweet."
ET spoke to Blanchett last week at the Hollywood premiere of Thor: Ragnarok, where she said she got fit "for the first time" in her life to play her villainous role as Hela.
"It doesn't sound like a lot but for 20 minutes a day -- which it sounds like nothing -- but I was exhausted before I even got on set," she recalled. "It was an extraordinary opportunity to, you know, finally get fit."