greyish brown color Taupe
The color you are referring to is often called taupe. Taupe is a neutral color that ranges from a light grayish-brown to a dark tan.
In Roald Dahl's book "Matilda," Matilda Wormwood is described as having dark eyes.
"Ecru" is a greyish-pale yellow or a light greyish-yellowish brown colour.
Ankerite
tan
beige
marsh
A greyish horse is called a grey horse nice and simple, so is a white horse ( called a grey that is ).
The soft greyish limestone that crumbles easily is called chalk.
wenge is a rich greyish brown with hints of copper
Ichneumon
Dun could be a dull greyish-brown colour, or a horse.