A method of characterizing a person's skin imperfections uses a digital color image-taking device to take at least one digital image of an area of skin including at least one imperfection to be characterized. An apparatus for characterizing the imperfections of the skin and a method for measuring the effectiveness of a treatment for skin imperfections use an active cosmetic, dermatological or pharmaceutical agent and further measure the effectiveness of a staining method aiming to attenuate or mask skin imperfections.