It's somewhat of a down year for the Pac 10 so I thought I pondered away from the basketball part and looked at the aesthetics of the conference in their jerseys and made the above ones (I was also influenced by players that EA has had in their games).
I've got to say Washington currently has the nicest looking jerseys in my opinion with their colors and stylistic lettering. Stanford's design is really unique and interesting, too. UCLA has a design that resonates with tradition and heritage.
As far as third jerseys go, it seems that yellow (or a shade of it) is really popular in the conference as half of the teams utilize a variation of that color. USC and ASU look too similar with their current yellow alternates. Honestly, I think the Golden Bears should demand the Pac 10 makes them the only exclusive team to have a yellow or "golden" jersey. As an alternate, I like Oregon States's 1995 orange jerseys. Arizona's red jerseys definitely live up to being wild to compliment an already nice contempory design.
Oregon's jerseys are definitely in their own world (I admire their penchant for uniqueness). I've got to say the Cougars definitely have consistently worned subpar designs over the years in my opinion. Then again, at least the WSU fans make up for the passion that's lost in the designs on their jerseys.
Go Pac 10!