noun, noun which may take the genitive case particle 'no'
yellowish gray; scum color
A grayish color with a yellowish tint, reminiscent of the scum that forms on the surface of lye or ash water. Used as a noun or no-adjective.
彼女は灰汁色のワンピースを着ていた。
She was wearing a yellowish-gray dress.
壁の色
The wall was painted a scum color.
Compound of 灰汁 (aku, 'lye, scum') and 色 (iro, 'color'). The exact historical derivation is uncertain, but the term refers to the yellowish-gray hue of lye scum.