a. and sb.
A. adj. Black or dark with a tinge of blue.
1853. Q. Rev., March, 309. The coarse blue-black locks of the North American squaw.
1871. M. Collins, Mrq. & Merch., II. i. 11. Face closely shaven, chin blue-black where the beard was … repressed.
B. sb. A pigment of this color.
1823. P. Nicholson, Pract. Build., 416. Blue-Black is the coal of some kind of wood burnt in a close heat.
1857. Ruskin, Elem. Drawing, 41. Take cakes of lake, of gamboge, of sepia, of blue-black, of cobalt.
Hence Blue-blackness.
1880. L. Wallace, Ben-Hur, II. iv. 96. A bank of blue-blackness over in the west which they knew to be mountains.
