Photo by Ruth Zavitz
S. eumorpha is highly variable with respect to flower colour and pattern. Pure white forms are available, and many specimens have varying degrees of lavender in the flower, with or without stripes and spots. Most have some yellow in the throat.
A pink form, often marketed as a pink variant of the species, probably was the result of hybridizing to the red-flowered members of the genus. A plant acquired as S. eumorpha (pink) was used as a parent, along with a pure white variant, to produce S. 'Pale Beauty'.