Method for selecting an elastic venous restraint orthosis intended to be slipped onto a lower limb of a patient. Acquisition of a photograph representing the skin of the limb and a calibration map including one or more calibration zones. The calibration map is placed on the limb in a position termed the “acquisition position.” Calibration of the photograph by the calibration zone or zones, in such a way that the representation of the skin on the photograph exhibits a calibrated colour. Selection, as a function of the calibrated colour, by computer and from a set of colours of a tone chart, of a tone chart colour, preferably of the tone chart colour closest to the calibrated colour, termed the “optimal colour,” and then determination, by computer, of an orthosis colour as a function of the tone chart colour selected. Selection of an orthosis exhibiting the orthosis colour.