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

2.   Each is covered with tightly interlocking patterns in dark brown pigment and could be mistaken for a contemporary painting.

3.   He adds brown pigment to the raw concrete for an old color and tone, and sandblasts the limestone to make it appear weathered.

4.   The agricultural biotechnology company said its scientists changed the color of cotton fiber by manipulating the gene for melanin, a dark brown pigment.