"Black coating" means, for purposes of 35 Ill. Adm. Code 218 and 219, a coating that meets both of the following criteria, based on Cielab color space, 0/45 geometry:
Maximum lightness of 23 units. For spherical geometry, specular included, maximum lightness of 33 units; and
Saturation of less than 2.8, where saturation equals the square root of A2 + B2.
Ill. Admin. Code tit. 35, § 211.735
Added at 34 Ill. Reg. 14119, effective September 14, 2010