Pigmentation

deciduous trees' and shrubs' autumnal change of leaf color from green to other colors

Hyperpigmentation is a condition characterized by the darkening of an area of the skin or nails due to an excess production of melanin, the pigment responsible for skin color. This increase in melanin can result from a variety of factors, including sun exposure, inflammation, trauma, certain medications, or underlying medical conditions.

A melanoblast is a precursor cell of a melanocyte. These cells migrate from the trunk neural crest cells (in terms of axial level from neck to posterior end) dorsolaterally between the ectoderm and dorsal surface of the somites.