University of Oregon students voted to adopt lemon yellow as their school color in 1893 to symbolize the official Oregon flower, the wild grape. Green was never officially authorized, but it has been used with yellow for so long that it is commonly understood to be the university’s second school color. Vintage memorabilia from the University of Oregon typically depict a medium to dark shade of green.
Citations in the World Almanac (listed by cover date; color information is from the previous year): lemon yellow (1896-1897); Oregon grape yellow (1900); lemon yellow (1902-1904); Oregon grape/green/yellow (1906-1908); green/yellow (1909-1911); green/lemon yellow (1912-1913); green/yellow (1914-1916); green/lemon yellow (1917-1935)
Although it may have initially been assigned a hood lining with a single color of lemon yellow, the academic hood lining design for the University of Oregon was first cited in a 1918 Encyclopedia Americana article on academic costume written by Gardner Cotrell Leonard, the Director of the Intercollegiate Bureau of Academic Costume (IBAC). Leonard stated that the university had been assigned a hood lining that was lemon yellow with a dark green chevron. This description was unchanged until a 1969 IBAC list, which lightened and brightened the chevron color to emerald green.
Here what is thought to have been the original IBAC assignment has been used, although it is possible that Oregon’s first hood lining design was lemon yellow alone, with a dark green chevron added later.