Every person has 2 eye color genes. When a couple produces a child, they each give 1 of their eye color genes to the child. Brown eyes are dominant and blue eyes are recessive. A person with 2 blue-eye genes will have blue eyes, and a person with 1 brown and 1 blue or 2 brown genes will have brown eyes. This means that if the child receives 1 brown eye gene and 1 blue eye gene from it’s parents, then the child’s eyes will be brown, but it will carry a blue eye gene which it could pass on to it’s children. This is how a brown-eyed couple can have blue-eyed children. Each person has 1 brown and 1 blue eye color gene resulting in them both having brown eyes. If they each pass on a blue-eye gene to their child, then that child will have blue eyes. There is a 25% chance of this happening.