A lotion such as a sunscreen includes a color indicator which colorizes the lotion until the lotion is applied to human skin, whereinafter the colored lotion changes color or turns clear. A physiological color indicator such as a pH indicator, a colorant, or a water-soluble dye such as coumarin can be used, alone or in combination, to colorize the lotion in accord with the invention. The lotion is suitable for use in any lotion, gel, mousse or medication that is best applied in an even and uniform manner to the skin. Accordingly, one preferred use of the invention is in UV-protection sunscreens so that a user can ensure even distribution of the sunscreen on the body. A sunscreen of the invention can also include an emollient, such as jacoba oil, an emulsifier, a surfactant, such as sorbitol, water, and a pH adjuster, such as triethanolamine.