Wiktionary
a. Of a dark bluish grey colour. alt. A dark bluish grey colour. n. A dark bluish grey colour.
Wikipedia
{{infobox color|
title=Slate gray|textcolor=white|
hex=708090|
r=112|g=128|b=144|
c=60|m=43|y=34|k=4|
h=210|s=22|v=56
source= X11}}
Slate roof
Slate as a tertiary colorSlate gray is a gray color with a slight azure tinge that is a representation of the average color of the material slate. As a tertiary color, slate is an equal mix of purple and green pigments.
Slaty, referring to this color, is often used to describe birds.
The first recorded use of slate gray as a color name in English was in 1705.
Usage examples of "slate gray".
Wearing a cloak of slate gray fisher fur over a mail coat inset with wolf teeth, he sat high atop the blue roan, contemplating Raif.
Its leaves were so dark as to be almost black, but the color was nowhere near that simple: on close inspection he saw shades of purple and deep blue and even deeper slate gray, colors that almost seemed to move.
The sky had turned a dense slate gray and they could all feel the warm wind on their faces.
Ceiling, floor, and three walls of the room were a featureless slate gray.
The sun stood barely its own height above the horizon, the sky overhead was pale slate gray, and thick purple clouds moving in from the sea threatened rain.
It didn't break but water gurgled out, turning dove gray to slate gray.
Her bladder let go, and the spreading stain as the dove gray rug turned to a darker slate gray around her bottom had caused her mother to actually shriek.