The Girls’ Generation girls wore the cheerleader outfits from the Oh! music video in their first Music Core performance and the pink and white outfits at Inkigayo. But what about the remaining outfits? Didn’t they wear a third set of outfits in the music video? Haven’t they worn that on stage?
The answer is: They did and they’re wearing it in the video below 
Credit: source video killerkim@jpopsuki
Unfortunately they put quite a distracting subtitle on this performance 
2010-02-11 (Thu) 01:15
Thank You Very Much!
2010-02-11 (Thu) 02:09
they are really cool and energetic.thanks for all the variety of oh!
2010-02-11 (Thu) 14:03
You’re welcome!
I have one more Girls’ Generation ready, then I’ll probably post some other stuff for a while