1. A method for producing a visual representation of the material of an object comprising: determining a spectral signature of the object in at least a portion of an input image, said spectral signature comprising a set of non-visible spectral components each being associated with a non-visible wavelength; comparing said spectral signature to each of a plurality of predetermined spectral signatures representing a respective plurality of materials and associated colors; based on said comparison, associating said spectral signature of said object with a material, thereby also associating said spectral signature with a respective color; and producing an output image having said color, thereby visually representing the material of said object as said color.