Abstract: In a first aspect, the method for simulating hair having variable colorimetry comprises preliminarily recording, in a first database (101), a given number of images of given hairstyles and, for each image of a given hairstyle, at least one associated colorimetric conversion matrix for obtaining said hairstyle image by applying said matrix to a reference hairstyle image of the same style; preliminarily recording, in a second database (102), at least one colorimetric conversion matrix per lotion for a given number of capillary lotions (L1-Lk); determining a resembling hairstyle image in said database by image recognition from an image of a hairstyle (401) retrieved from an initial digital image of a person (400); identifying, in the first database, a reference hairstyle image of the same style as the style of the resembling hairstyle image and a calorimetric conversion matrix associated with the resembling hairstyle image; creating an avatar (410) from the initial digital image of the person (400), which avatar