McAdams, 37, who also posed for photos with her co-stars Benedict Cumberbatch and Tilda Swinton at the premiere, rocked the bold look with a sleek ponytail as she strutted her stuff on the carpet. Her glam style choice also showed off her impressive stems and toned bod.
"It's kind of one of the more psychedelic comics. It was written in the '70s, I think when the writers were experimenting with psychedelics," she told DeGeneres. "So it's pretty trippy and kind of cool. It deals with magic and the occult and parallel universes and all this wild stuff."
For more from the cast of Doctor Strange, watch the clip below.