As I expected against Portland State—a team that wears green and black—the Ducks are wearing a yellow-heavy ensemble with black helmet with "carbon fiber" wings.
The last time the ducks wore this combo of black-yellow-yellow was a game 2 win vs Virginia in 2016 during the Mark Helfrich era. But they did wear nightmare-yellow-yellow in week 3 of 2019.
Carbon fiber was a motif used a lot in the last 15 years but not much lately. Carbon fiber was especially prominent in the 2010-2014 era between the two National Championship games. It was first was worn in the Civil War in 2020 that marked the perfect Pac-12 season for Oregon.