Black:

Natural Carbonized Charcoal bamboo fiber from England. This bamboo gets its color from being carbonized and heated. It is not dyed. This bamboo has many benefits including reducing static, softening your laundry, and reducing drying time.
My dryer balls are safe with whites, darks, delicates, clothe diapers, and really any laundry!

White: 

Natural white bast bamboo fiber. Made from bamboo pulp. Unbleached, not dyed, natural color without chemicals. Reduces dryer time on laundry by absorbing moisture from the clothes. Softens clothing. Gets the wrinkles out, helps with static. Replaces dryer sheets as an all natural and heathy alternative. Add essential oils to the balls to scent laundry!