Common traits of all horses with a basic colour black

• The coat is black, or almost black.
• Mane and tail are black.

Genetics

Possible gene combinations:  aaEE, aaEe.

There must always be a dominant E (to provide the black pigment), but there must only be recessive a (no restriction of the black pigment). This means that two blacks can never have a bay foal.

Shades of black

• Jet or raven black: coat, mane and tail are deep blue-black and do not fade when exposed to sunlight.
• Summer or fading black: black coat which fades to brown-black when exposed to sunlight, mane and tail generally remain jet black. 
• Seal brown (pangare): coat, mane and tail black, lighter points on muzzle, under belly, inside of thighs.