slate-color

In stormy weather they are sometimes of a dark slate-color.

Walden 2004

The lava rock was of a deep, dull slate-color, which at a distance looked black; and the blackness which thus succeeded to the whiteness of the snow behind us seemed like the funeral pall of nature.

A Strange Manuscript Found in a Copper Cylinder James De Mille

Plant, in height and general habit, similar to Darling's Early; ears six to eight inches in length, uniformly eight-rowed; kernels roundish, flattened, deep slate-color, much shrivelled at maturity.

The Field and Garden Vegetables of America Containing Full Descriptions of Nearly Eleven Hundred Species and Varietes; With Directions for Propagation, Culture and Use. Fearing Burr

The walls were unpainted, but turned by the slow action of sun and air and rain to a quiet dove - or slate-color.

The Atlantic Monthly, Volume 05, No. 29, March, 1860 Various

They were of a slate-color, and might, I suppose, have been able to shift for themselves.

The Atlantic Monthly, Volume 17, No. 101, March, 1866 Various

As he looked down into the large gray eyes, really slate-color in their natural darkness, made the darker by the shadows of the long lashes, he entirely forgot place and circumstances; ceased to think whose turn it was to speak; even forgot to think whether he was enjoying the moment.

The Honorable Peter Stirling and What People Thought of Him Ford, Paul L 1894

Wild-geese they were, or, as some call them, Canada geese; nearly as large as our domestic geese, and of a gray slate-color.

Left on Labrador or, The cruise of the Schooner-yacht 'Curlew.' as Recorded by 'Wash.' 1887

As he looked down into the large gray eyes, really slate-color in their natural darkness, made the darker by the shadows of the long lashes, he entirely forgot place and circumstances; ceased to think whose turn it was to speak; even forgot to think whether he was enjoying the moment.

The Honorable Peter Stirling and What People Thought of Him Paul Leicester Ford 1883

The male is of a bluish slate-color; the female reddish-brown, like the hen-hawk, with a white rump.

Bird Stories from Burroughs Sketches of Bird Life Taken from the Works of John Burroughs John Burroughs 1879

A small family in dark slate-color and white, with a curious taste for the antique cave-dwelling, was next on our list.

Little Brothers of the Air Olive Thorne Miller 1874