The invention relates to a method for putting color to glass by irradiating a silicate glass, containing a non-bridging oxygen in its structure, with a laser light, thereby forming a non-bridging oxygen hole center therein to put a color to the glass. The invention further relates to a method for putting color to glass by irradiating a silver-ion-containing glass with a high-energy light, thereby forming silver particles in the glass through aggregation of silver ions to put a color to the glass. The invention further relates to a method for erasing color from colored glass by irradiating a colored portion of a glass with a laser light to selectively heat the colored portion by using a laser irradiation apparatus comprising (a) a laser oscillator, (b) a light modulator, (c) a condenser lens mounted on a linear translator, (d) an objective lens, and (e) a galvanometer mirror.