Sandra Bullock was sporting a new hairdo earlier this week that really had people talking. It seemed that she had joined the likes of Alanis Morissette, Sophia Bush, and Lena Dunham in going blonde.

The new look was spotted on the set of her new George Clooney-directed politcal thriller, Our Brand is Crisis, in New Orleans. She plays an apparently blonde retired political analyst

However, while Sandra Bullock looks great either way, the blonde hair was not to last.

Just two days later, she was photographed with her gorgeous dark locks again.

Could the blonde hair be a wig or is it the world’s best and quickest dye job?

Sandra Bullock has dyed her hair before for movie roles.

In 2009, she died her hair blonde to play Leigh Tuohy in The Blind Side. Later the same year, she did it again for her role in All About Steve. Then, in 2011, Sandra Bullock went blonde for Extremely Loud and Incredibly Close.

Sandra Bullock and George Clooney are taking a break from filming for his wedding to Amal Alamuddin in Italy. George and Amal are hosting a small welcome party for their guests on Friday at the Belmond Hotel Cipriani in Venice.

Guests who have already arrived include Cindy Crawford and her husband, Rande Gerber, Matt and Luciana Damon, John Krasinski and Emily Blunt, Richard Kind, Ellen Barkin, Gabriel Byrne, Grant Heslov and Miguel Ferre.

The actual ceremony is said to be taking place on Monday, and festivities will last all weekend.

But, not to worry. Venice is ready.

“Ever since he admitted he would be marrying in Venice a few weeks ago, everyone wants to be in on it,” says local Liliana Sermonetta.

“Where are they staying, what are they eating, will they take a gondola ride? It’ll be difficult for Clooney to outdo Salma Hayek and François-Henri Pinault’s wedding. The whole of Hollywood moved here for three days!”

So what will Sandra Bullock’s hair look like at the wedding? We shall soon find out!