I kept thinking I saw rust this summer on many of my daylilies. I started reading on here and googling about it. I read somewhere that rust will easily rub off on your fingers, and there was a picture of someones hand with what looked like daylily pollen on their fingers. I didn't have that on my daylily leaves, just spots, so maybe it was leaf streak.
Since then, all those ugly, rusty looking leaves have died off and new leaves appeared in their place. The plants look beautiful, and healthy! Just in time for winter!