An object of the invention is to provide titanium dioxide coloring particles capable of developing colors other than red and yellow while maintaining non-toxicity of titanium dioxide and a titanium dioxide particle mixture containing the titanium dioxide coloring particles, and to provide a method capable of producing the titanium dioxide coloring particles exhibiting the excellent properties by a simple process with a small environmental load. The invention relates to titanium dioxide coloring particles having a brookite type or rutile type crystal structure and co-doped with at least nitrogen and boron, a titanium dioxide particle mixture containing the titanium dioxide coloring particles, and a method for producing the titanium dioxide coloring particles in which a hydrothermal reaction of titanium diboride is caused in presence of an acid or urea, and then a nitriding treatment is performed in an ammonia gas atmosphere or by mixing with urea or carbon nitride.

An object of the invention is to provide titanium dioxide coloring particles capable of developing colors other than red and yellow while maintaining non-toxicity of titanium dioxide and a titanium dioxide particle mixture containing the titanium dioxide coloring particles, and to provide a method capable of producing the titanium dioxide coloring particles exhibiting the excellent properties by a simple process with a small environmental load. The invention relates to titanium dioxide coloring particles having a brookite type or rutile type crystal structure and co-doped with at least nitrogen and boron, a titanium dioxide particle mixture containing the titanium dioxide coloring particles, and a method for producing the titanium dioxide coloring particles in which a hydrothermal reaction of titanium diboride is caused in presence of an acid or urea, and then a nitriding treatment is performed in an ammonia gas atmosphere or by mixing with urea or carbon nitride.