What is the medical term meaning any condition of unusual deposits of black pigment in the body?

Disease marked by abnormal pigmentation may be called chromatosis or melanosis, or melanopathy. Amelanism or amelanosis is the term used for a lack of pigmentation of the skin.

Some examples of chromatosis or melanosis:

• Vitiligo, an autoimmune disorder characterized by splotchy white patches of unpigmented skin.
• chloasma,
• Addison's disease
• hepatitis

Chromatosis, melanosis
Melanopathy is a term for disease of excess pigmentation.
melanopathy
Chromatosis, melanosis
melonopathy