They are usually called 'fleabitten greys
Roan
certainly not, there is speckled hen, white horse. And Lots More.
Yes, speckled can be an adjective--a speckled egg.
A purple roan horse has a unique coat color that combines shades of purple and white hairs, creating a speckled or mottled appearance. This coloration is rare and distinct, making the horse easily recognizable.
"Speckled" has two syllables.
a speckled rock
The bird's egg was speckled with tiny dots of brown.
a speckled band
Speckled moray was created in 1932.
Speckled Bird was created in 1993.
Speckled Warbler was created in 1801.
Speckled Mousebird was created in 1789.