1662, "crayons, chalk-like pigment used in crayons," from Fr.
pastel "crayon," from It.
pastello "a pastel," lit. "material reduced to a paste," from L.L.
pastellus "dye from the leaves of the woad plant," dim. of
pasta (see
pasta). Meaning "pale or light color" first recorded 1899.
"The soft, wraith-like tints ... are now in fashion again. The modern name for them is 'pastels,' ... for these soft, half-faded tones bear the same relation to real colours as pastels do to oil-paintings." [(London) Daily News, Oct. 21, 1899]