Crimson & Amber & Cobalt

Crimson is the carmine — the deep vivid cool-red of carmine lake (derived from cochineal, Dactylopius coccus, an insect parasite of Opuntia cactus in Mexico and the Canary Islands), the primary transparent red used by Renoir throughout his career. Art historians have documented Renoir's specific preference for carmine over vermilion (the opaque mercury-sulfide red) for the delicate, luminous quality it creates in wet paint — carmine's transparency allows warm underlayers to show through, creating the specific warm-glowing quality of Renoir's painted skin and flowers. Amber is the yellow-amber — the warm deep-golden of Renoir's mixed yellow element, combining chrome yellow and Naples yellow (lead antimonate) to create the specific warm amber-golden of Parisian summer sunlight. Renoir's yellow handling is the most celebrated single technical achievement in Impressionism — his ability to render sunlight on skin, on cloth, on water, and on foliage using amber-yellow mixed with the warm light of his palette creates the specific warmth that makes his paintings feel more solar and more physically warm than any other Impressionist. Cobalt is the outdoor sky — the deep vivid blue of cobalt blue pigment (cobalt aluminate, CoAl₂O₄), the standard 19th-century outdoor painting sky blue. Cobalt blue's specific deep vivid quality (approximately 222° hue, high saturation) was the preferred sky blue of virtually every Impressionist painter — it gave outdoor scenes their specific clear, vivid-blue quality of an unclouded Paris summer sky.