(Undated)  --  The 2-and-1 Oregon Ducks return to Autzen Stadium to open Pac-12 play against the Colorado Buffaloes on Saturday afternoon.  Oregon is coming off a 35-32 loss to Nebraska.  Oregon State will face its toughest matchup of the young season when Boise State comes to town on Saturday.  The 1-and-1 Beavers will try to give the Broncos their first loss of the year.  Portland State will look to end a two-game losing streak when it hits the road against Southern Utah on Saturday night.  The Vikings are 1-and-2 on the season.