Abstract: An object of the present invention is to provide a technique for improving the lightfastness of a dyed anodic oxide film of aluminum or an aluminum alloy. Provided are a Lightfastness improver for a dyed anodic oxide film of aluminum or an aluminum alloy, and a method for improving the Lightfastness of the film.

Abstract: An object of the present, invention is to provide a chemical conversion surface, treatment solution, that is capable of forming a chemical conversion film with excellent corrosion resistance and designability on articles having aluminum or aluminum alloy surfaces by using steps similar to those of known chemical conversion treatments without using hexavalent chromium, trivalent chromium, fluorine, or other components that create a significant burden on the environment. The present invention relates to a chemical conversion treatment solution for aluminum or aluminum alloys, comprising an alkaline aqueous solution containing a permanganic acid compound and at least one metal oxygen acid compound selected from the group consisting of vanadic acid compounds, molybdic acid compounds, tungstic acid compounds, zirconic acid compounds, and niobic acid compounds.