Disclosed is a system of natural colors consisting of thousands of colored powders of mineral origin and of materials in or on which pigments have been applied and, afterwards, submitted to at least one thermal treatment and/or irradiation. These natural colors cover the totality of the visible spectrum and offer a great variety of tones, tints and reflections from white to black, including all the rainbow colors. The powders of this system are obtained by mechanical, chemical, thermal and/or physical processes and are used alone or in combination. They are particularly useful to color materials and, more especially those used in the construction and architectural fields.