Perhaps ‘red’ came to have unwanted connotations? Or is “red” a technical term amongst gardeners?
HOLLYHOCK, 1936 (first sold 1950)
Small but stunning ‘Hollyhock’ is an almost unbelievably deep, deep rose, or “red” as it was known in the 1800s.Source: “Heirloom Hyacinth Bulbs” (p. 2) at Old House Gardens (scroll down).