I illustrated mullein pinks with a white flower because that image shows off their fuzzy nature. Pink flowers are more common, perhaps because they're more cultivated. Mullein pink is an old time garden plant, somewhat neglected in these days of such showy cultivars. Why watch Elsa walk into the cafe, when you can have a car chase?
I have not discovered the function of the small appendages on the petals at the opening of the tube in Silene. Perhaps they help direct pollinators.