If the condition worsen of lasts longer than three weeks be sure to contact your baby's doctor. As a baby becomes a child, their hair will often change color. It is common for children who had very light colored hair as a newborn or young baby to have darker hair as they get older. No one really knows why this happens, but it is believed to be related to the pigment of the hair. It is believed that as the pigment cells gradually mature they produce more pigment in the child's hair, making it darker.
Light hair is basically hair that has an absence of pigment.
A lot of people will tell you that as babies they were blondes but that their hair turned darker as they got older. This is happens commonly. As children get older they start to have very definite opinions of how they want to wear their hair. This hairstyle preference will surface in childhood and continue throughout life. Hairstyle preference that starts to surface in early childhood will continue throughout the teen years and into adulthood.