'Thrones' star Natalie Dormer wears red

Ann Oldenburg | USA TODAY

In light of the "red wedding" episode that has kept Game of Thrones fans buzzing since Sunday's surprising episode, it was only fitting that Natalie Dormer opted for a red dress Tuesday in Spain.

The Thrones star, who plays Margaery Tyrell (betrothed to evil King Joffrey) in the HBO series, posed for cameras during a photocall in the Game of Thrones promotion at Nocturna fantastic film festival at Palafox Cinema in Madrid.

Dormer told ET before Sunday's episode that fans would be in for a shocking end to the season, which wraps up on Sunday at 9 p.m.

"The fans will go through a very traumatic climax of 30 hours of television — the finale and the penultimate episodes will flip everything on its head," she said.

"Some of the stories get resolved, the people you would have thought invincible end up in a very unhappy dark place and the ones you would have never bet on find themselves in promising circumstances."

Dormer, 31, said she thinks fans "are going to feel quite traumatized about a lot of the characters they've grown close to over the last three seasons. It will have a real shock factor. And yet, so brilliantly, it almost wipes the slate clean for season four, which we start shooting in July."