Ochre refers to any rock rich in iron oxide that yields red, yellow, or brown pigments.

赭石是指任何富含氧化铁的岩石，能产生红色、黄色或棕色颜料。

Overall the painting is very dark and relies largely on the use of sombre brown, black, and grey pigments.

总体来说，这幅画非常暗，很大程度上依赖于暗棕色、黑色和灰色颜料的使用。

Melanin is the dark brown pigment of the hair, skin and eyes.

【pigment】黑色素是头发、皮肤以及眼睛中的深棕色色素。

Freckles are just your average normal skin cells that contain an extra bit of melanin, a special dark brown pigment that helps protect your skin like sunscreen.

雀斑只不过是普通的正常皮肤细胞，不过里面含有额外的一点黑色素，这是一种特殊的深褐色色素，可以像防晒霜一样保护你的皮肤。