There are certain light reds which show an extraordinary brightness and beautiful undertone on cream or "natural white" enameled papers, while on paper slightly toned with blue the beautiful effect is gone.
-- Emory Cobb Andrews, Color and its application to printing
One of the most common mistakes women with ivory/ beige skin make is choosing a foundation with a pink undertone.
-- Robert Jones, Looking Younger: Makeovers That Make You Look as Young as You Feel
Undertone is first used to describe in a visual sense around 1800.