Though most believe Penn State invented the whiteout, period images and newspaper articles show Texas fans wore their fancy whites eighty years earlier.
Interesting story. I do have one question: did Texas refer to their dressing in white as a "whiteout?" If not, perhaps Penn State invented the expression for fans dressing all in white. It seems that many schools have copied that idea since 2004. Just last week Illinois had an orange-out against Penn State. It did not work.
To my knowledge, Texas never referred to the all-white clothing as a whiteout. The earliest reference I've found of whiteout in the context of fans of a team wearing all white for a game came in 1990, when the Tri-City Americans of the Western Hockey League (a major junior league) used the term for their 11/21/90 game with Victoria.