The term for Nebraska’s first-string defensive team originated back in the mid-1960s under legendary head coach Bob Devaney when the coaching staff wanted the offense and defense to wear different colors in practice. The black pullovers were distributed before practice each day and had to be earned, with the other defensive players wearing gray. The tradition and mystique grew with the success of the defensive team throughout the rest of the decade, culminating in national championships in 1970 and 1971.