IIRC, the last time the women wore gold unis was vs K-State in the 2008 Big 12 tourney -- the game where Lacey scored with a few seconds left and KSU had a shot roll out at the horn.
[EDIT: I guess they were worn the next day vs. A&M, too.]
That was in the old uni set, right before the logo change. I don't think they even have a gold uni in the current set.
The golds rarely came out, maybe once every other year. Usually it was against Texas Tech, either in Lubbock or in Kansas City, during the Taylor/Welle era.