Manufacturing method for colored products and ink ejection device

An ink ejection device that manufactures a colored product which is a product colored using ink, the ink ejection device comprising:

• a plurality of color ink heads which are a plurality of inkjet heads that eject color inks different from each other;
• a colorless ink head, which is an inkjet head that ejects colorless ink;
• and
• a controller, configured to control operations of the plurality of color ink heads and the colorless ink head, wherein
• the controller is configured to causes the plurality of color ink heads and the colorless ink head to:
• form a plurality of coloring regions in an overlapping manner in a normal direction so that a thickness in the normal direction of a surface of the colored product each becomes a predetermined thickness,
• form, among the plurality of coloring regions, a surface side colored region, which is a region located closest to the surface of the colored product in the normal direction, using at least the color ink ejected from any of the color ink heads, and
• form, among the plurality of coloring regions, an inner colored region, which is a region located farther from the surface of the colored product than the surface side colored region in the normal direction, using at least the color ink ejected from any of the color ink heads and the colorless ink ejected from the colorless ink head.