What color is associated with eumelanin?

Eumelanin is a type of melanin that is primarily responsible for the darker shades of hair, skin, and eyes. It comes in two varieties: black eumelanin and brown eumelanin. This pigment is prevalent in individuals with darker hair and skin tones and contributes to the rich colors observed in naturally dark hair, ranging from deep brown to jet black.

The other options represent different types of pigments or colors. For example, red hair is associated with pheomelanin, while blonde hair indicates a lower concentration of eumelanin. White is often the result of a lack of melanin altogether, leading to albinism or gray hair due to age. The association of eumelanin with brown to black is well established in the study of hair and skin pigmentation, making this the correct choice in the context of the question.