Kim looked elegant in a gold satin dress with a matching coat. Her hair, which is naturally dark brown, is currently a blonde ombre, perfectly matching her outfit.
Khloe opted for a white mini dress with long sleeves, while their mother wore a black and white jacket, shiny skirt and boots.
The event honored Winfrey, who was presented with the coveted Sherry Lansing Leadership Award, named after the Hollywood mogul.
The couple's rep told People magazine, "Idina Menzel and Taye Diggs have jointly decided to separate at this time. Their primary focus and concern is for their son. We ask that you respect their privacy during this time."
The pair met in 1995 while performing in the original Broadway production of "Rent." They wed in January of 2003 and have a son named Walker, 4.
Menzel currently voices a role in the Disney animated film "Frozen." She has had a successful Broadway career and has released several albums.