1. A method for determining shade of a patient's tooth, wherein the method comprises: obtaining a digital 3D representation of the tooth, where the digital 3D representation comprises shape data and texture data for the tooth; determining a tooth shade value for at least one point on the tooth based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values; deriving a certainty score expressing the certainty of the determined tooth shade value; and generating a visual representation of the certainty score and displaying this visual representation in a user interface, wherein the visual representation of the certainty score is at least one of a binary code, a bar structure with a color gradient, a numerical value, and a comparison between the texture date and the known texture value of the determined tooth shade value.