The name "panther" is often limited to the black variants of the species, but is also used to refer to those which are normally-colored for the species (tawny or spotted), or to white color variants: white panthers.

Melanism

Melanism in the jaguar (Panthera onca), is conferred by a dominant allele, and in the leopard (Panthera pardus) by a recessive allele. Close examination of the color of these black cats will show that the typical markings are still there, but are hidden by the excess black pigment melanin, giving an effect similar to that of printed silk. Melanistic and non-melanistic animals can be littermates. Albino or leucistic individuals of the same species are known as white panthers.

It is thought that melanism may confer a selective advantage under certain conditions since it is more common in regions of dense forest, where light levels are lower. Recent, preliminary studies also suggest that melanism might be linked to beneficial mutations in the immune system.

Melanistic leopards