There was a time when black was the only appropriate color to wear to a funeral. Today, only family members are expected to wear black unless you have been asked to be a pallbearer or have been asked to be seated with the family.
Even though black clothing is not required, but very appropriate, try not to wear any bright colors or loud prints. Your clothing choice should reflect the solemness of the occasion.
Children should never ever wear black. They should wear their Sunday best attire to a funeral.