Katherine Heigl blonde hair

Katherine Heigl shows off her new, platinum blonde hairdo. Photo: Jason Merritt, Getty Images

While last night's season opener of "Grey's Anatomy" just wasn't the same without Izzy, Katherine Heigl has been busy with yet another movie premiere -- and yet another hair color.

The 31-year-old star appeared at a press conference for the Jason Debus Heigl Foundation yesterday with tresses that were not just blonde, but ones that tipped the scales towards a much lighter, platinum version.

Heigl has certainly not been shy about switching up her 'do over the years, reverting all the way from blonde to brunette and back again several times over. And even though this Hollywood mom graces the October cover of InStyle with her new lighter locks, yesterday was her first public debut.

As much as we think this actress is a definite beauty, the editors at StyleList breathed a collective sigh of relief that she ditched the big brown bouffant hairdo she was sporting for her last movie release.

Heigl's new film (where she dons golden blonde locks), "Life As We Know It" opens October 8.

In the meantime, tell us, do you like her best as a blonde, brunette or somewhere in between? Leave a comment below. Then take a look at photos of Heigl at another movie premiere with, you guessed it, another hair color.