It was 1971, and everybody was into "doing their own thing," so we wore (long) formal gowns, any style, any color. It was nice because each girl could chose the outfit that best suited her......but it gave the chapter no unity.
Next year, we had the same sky blue fabric, but each person chose her own dress pattern. Now THAT was a big success!
A few years later, as advisor for a chapter, I made a couple of dresses for girls out of a dusty blue polyester fabric (hey, it was THE fabric of the '70s!). Same pattern for everybody...they turned out beautifully.
All I've seen lately is black.
It's probably about time for a change!