I only have two stalks of hollyhocks. The one white one has frilly multiple petals in its flowers. The other one is just a plain looking white hollyhock. I did see pink the other day and I was surprised. I now see that the shriveling white flower turns pink as it shrinks.
This single plain flower is shown below. When genetics is taught in high school, the traits of a hollyhock are used as they apparently have dominate traits that make them grow with different traits. My neighbors many hollyhocks directly across the street are mostly pink.