Method for Manufacturing Colored Aluminum Product or Colored Aluminum Alloy Product, Pigment Composition for Coloration, and Colored Aluminum Product or Colored Aluminum Alloy Product

A method for manufacturing a colored aluminum product or a colored aluminum alloy product, comprising the following steps of:

• (i) subjecting a substrate made of aluminum or aluminum alloy to an anodic oxidation in a treatment solution containing phosphoric acid to form an anodic oxidation film having a plurality of pores on a surface of the substrate;
• (ii) washing the substrate with water, where phosphoric acid ions remain in the plurality of the pores in the anodic oxidation film on a surface of the substrate after washing the substrate;
• (iii) drying the substrate with hot air having a temperature between 70° C. and 150° C., thereby removing the phosphoric acid ions remaining in the plurality of the pores in the anodic oxidation film on the surface of the substrate;
• and
• (iv) immersing the substrate dried with the hot air in a pigment composition for coloration comprising pigment particles, a dispersing agent, and water to fill the pigment particles into a plurality of the pores in the anodic oxidation film on the surface of the substrate without using electrophoresis, thereby performing the coloration,
• wherein each of the pores in the anodic oxidation film has a pore size between 20 and 200 nm and a depth between 1 and 50 μm in a thickness direction, and
• wherein the pigment particles in the pigment composition have a particle size distribution in which a particle size of D 80 is less than the pore size of a minimum pore of the plurality of the pores in the anodic oxidation film in a state in which the pigment particles are dispersed in the pigment composition.