Grey was once a common color in the Akhal-Teke (though never as common as it is in the Arabian, Caspian or in other strains of Turkoman), and of the earliest line stallions, four, Arab, Ak Sakal, Posman and Kir Sakar, were greys. As with the Arabian, the grey Akhal-Teke (and the grey Caspian) tends to become completely white with age, and a glowing white Turkoman is truly a sight to see.

Greying with age from birth is a very rare phenomenon in wild animals; the grey wolf and the beluga whale are the only non-domesticated species which show this trait. Greying from birth is, on the other hand, fairly common in domesticated animals; dogs (as would be expected), horses and ferrets show it commonly. Grey is a simple dominant trait: at least one parent of a grey animal will also be grey. A horse who is homozygous for grey will produce only grey offspring. Grey is completely independent of other colors, patterns or markings and can occur in combination with any of them.

There are a number of terms for various shades of grey, and for the appearance of grey over other colors. In the eastern United States, an "iron grey" is a medium shade of grey, and a "white-grey" is a grey with just a minimum of dark hairs left.