A coating composition comprising a component, a component, and a component, wherein the component is at least one silicon-containing substance selected from the group consisting of organosilicon compounds of general formula: (R 1) a (R 3) b Si(OR 2) 4-(a+b) (wherein each of R 1 and R 3 is a C 1-35 alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkenyl group, or an organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, a ureido group, an ether group, an amino group, or a cyano group, and is bonded to a silicon atom through a Si-C bond; R 2 is a C 1-8 alkyl group, an alkoxyalkyl group, or an acyl group; and each of a and b is an integer of 0, 1, or 2, and a + b is an integer of 0, 1, or 2); or general formula: [(R 4) c Si 3-c] 2 Y (wherein R 4 is a C 1-5 alkyl group; X is a C 1-4 alkyl group or an acyl group; Y is a methylene group or a C 2-20 alkylene group; and c is an integer of 0 or 1); and hydrolysates thereof; the silicon-containing substance contains at least one hydrolysate of the organosilicon compounds, and is contained in an amount of 20 to 85% by mass in the coating composition; the component is a modified metal oxide colloidal particle having a primary particle diameter of 2 to 100 nm, which includes a metal oxide colloidal particle having a primary particle diameter of 2 to 60 nm as a core, whose surface is coated with a coating formed of an acidic oxide colloidal particle having a primary particle diameter of 1 to 4 nm, and the colloidal particle is contained in an amount of 10 to 60% by mass in the coating composition; and the component is a silica colloidal particle having a primary particle diameter of 2 to 80 nm, and is contained in an amount of 0.1 to 30% by mass in the coating composition, obtainable by performing the following steps (a) and (b): step (a): mixing the component and the component with at least partially or completely hydrolyze the component; and step (b): mixing the mixture obtained in step (a) containing the at least partially or completely hydrolyzed product of the component, with the component. the component is at least one silicon-containing substance selected from the group consisting of organosilicon compounds of general formula: (R 1) a (R 3) b Si(OR 2) 4-(a+b) (wherein each of R 1 and R 3 is a C 1-35 alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkenyl group, or an organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, a ureido group, an ether group, an amino group, or a cyano group, and is bonded to a silicon atom through a Si-C bond; R 2 is a C 1-8 alkyl group, an alkoxyalkyl group, or an acyl group; and each of a and b is an integer of 0, 1, or 2, and a + b is an integer of 0, 1, or 2); or general formula: [(R 4) c Si 3-c] 2 Y (wherein R 4 is a C 1-5 alkyl group; X is a C 1-4 alkyl group or an acyl group; Y is a methylene group or a C 2-20 alkylene group; and c is an integer of 0 or 1); and hydrolysates thereof; the silicon-containing substance contains at least one hydrolysate of the organosilicon compounds, and is contained in an amount of 20 to 85% by mass in the coating composition; the component is a modified metal oxide colloidal particle having a primary particle diameter of 2 to 100 nm, which includes a metal oxide colloidal particle having a primary particle diameter of 2 to 60 nm as a core, whose surface is coated with a coating formed of an acidic oxide colloidal particle having a primary particle diameter of 1 to 4 nm, and the colloidal particle is contained in an amount of 10 to 60% by mass in the coating composition; and the component is a silica colloidal particle having a primary particle diameter of 2 to 80 nm, and is contained in an amount of 0.1 to 30% by mass in the coating composition, obtainable by performing the following steps (a) and (b): step (a): mixing the component and the component with at least partially or completely hydrolyze the component; and step (b): mixing the mixture obtained in step (a) containing the at least partially or completely hydrolyzed product of the component, with the component. step (a): mixing the component and the component with at least partially or completely hydrolyze the component; and step (b): mixing the mixture obtained in step (a) containing the at least partially or completely hydrolyzed product of the component, with the component.