Moles are not freckles. Mostly, they are easy to tell apart. Moles can be dark brown, pink, or a neutral shade. Moles will often appear at birth or childhood and continue to grow at a pace with a person's natural growth. They are caused by an overproduction of cells and are not often harmful. However, some moles may be a warning sign of melanoma. If a mole is asymmetrical, has irregular borders, has changed colors or has multiple colors, or has grown to a large diameter, these could be signs of cancerous growth. If you are concerned for any reason, the safest and quickest option to achieve peace of mind is always to see a health professional.