I have had a couple that out of nowhere put out a variegated fan but it will revert back if left attached to the others from what I am told. I assume that is correct because mine are no longer variegated and have not done it again. I don't know what makes a non-variegated daylily produce variegated foliage.
There are variegated daylilies I just don't know the names off the top of my head though.
