I looked up and found that there is bearded iris mosaic virus, Iris mild mosaic virus and iris severe mosaic virus which are spread by aphids. Some of the symptoms are the leaves may become light green or yellow flecks and mottles(streaking). Flowers may develop patches of irregular color or breaks in the color. The plant loses vigor or become stunted. If they are infected, they will not recover. Dig them up, burn or bury them and keep aphids under control. I don't think this was my problem as they didn't have any of these symptoms and I never had an aphid problem (knock on wood). It is an isolated bed so I'll keep an eye on them this coming year.
