Like so many common beauty ailments, spotty and uneven skin can seem to develop out of nowhere. But what causes uneven skin tone? If you have an uneven skin tone read on for five common causes.Sun ExposureWe all know that UV rays can affect the color of our skin, whether it results in desirable tans or unsightly burns. But the sun is also the all-too-frequent culprit behind hyperpigmentation, or uneven spotting. Always apply sunscreen, diligently, evenly, and every single day, to minimize your risk of sun damage. AcneThey aren’t called “acne scars” for nothing. After blemishes subside, it’s not uncommon for darker spots to linger on the skin in their place, according to the American Osteopathic College of Dermatology.  GeneticsDifferent skin colors can hint at varying skin thickness and sensitivity. Black and brown skin is often thinner, making it more prone to melasma and post-inflammatory hyperpigmentation, according to The American Academy of Dermatology (AAD). HormonesAny change in hormonal balance can offset the production of melanocytes, which prompt the coloration of the skin, according to American Family Physician. So a slightly less even skin tone should come as no surprise during times of hormonal flux, such as puberty, menstruation, menopause, and especially pregnancy. Skin InjuriesDamaged skin can gradually cause an increase of pigment production in a given area, according to the AAD. To avoid this, refrain from using any overly harsh products and picking at flaking or acne-plagued skin.