Dark is dominant

In science I always learned that dark is dominant. I've had brown/auburn hair my whole life I have never been blonde. I have green eyes. My boy's both have blonde hair blue eyes just like their daddy. They also both look just like their daddy people always ask if they're twins. Why? Lol will I ever have a brunette child? ( Obviously I know noone knows the answer to this) do you have kids with two different color hair?