丹 / 鉛丹

に / えんたん

丹 is the historical lead-oxide pigment behind the color name 丹色; the name long outlived the specific material.

Tobunken's 彩色DB records 丹 (red lead, Pb₃O₄) in Nara-period documents such as the Hōryū-ji inventory.

Lead-red pigment context only. It is not a measured value, and 丹色 today is a digital approximation.