I have brown hair. It's really very common.
how did you get brown hair?
I have higher levels of a pigment called eumelanin 
did you inherit this property?
I'm caucasian so this hair color is common in my ethnic group
can you tell me more about this pigment eumelanin?
Eumelanin is the pigment that makes hair darker, so the more eumalinin that is present the darker the hair color