A thermoplastic resin composition, comprising: 10 to 50 % by weight in total of an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-1) containing alkyl acrylate rubber having an average particle diameter of 0.33 to 0.5 μm and an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-2) containing alkyl acrylate rubber having an average particle diameter of 0.05 to 0.2 μm; 0 to 30 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (B-1) comprising 67 to 75 % by weight of an aromatic vinyl compound and 25 to 33 % by weight of a vinyl cyanide compound; 20 to 70 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (B-2) comprising 70 to 75 % by weight of an aromatic vinyl compound and 25 to 30 % by weight of a vinyl cyanide compound; and 0.5 to 10 % by weight of a polyamide resin having a melting temperature (Tm) of 250 °C or higher, wherein the graft copolymer (A-1) and the graft copolymer (A-2) each have a coloring power coverage value of 20 % or more as calculated by Equation 1 below: X = A / S × 100, wherein S represents a content (wt%) of a fusible material (sol) after dissolving the graft copolymers in acetone and performing centrifugation, and A represents a content (wt%) of the vinyl cyanide compound in the fusible material (sol) after dissolving the graft copolymers in acetone and performing centrifugation, wherein the average particle diameter is measured by dynamic light scattering as disclosed in the description, the thermoplastic resin composition being free of a heat resistant styrene-based resin other than the aromatic vinyl compound-vinyl cyanide compound copolymers (B-1) and (B-2), and excluding thermoplastic resin compositions according to Examples 1 to 8 of EP 4 108 722 A1. 10 to 50 % by weight in total of an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-1) containing alkyl acrylate rubber having an average particle diameter of 0.33 to 0.5 μm and an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-2) containing alkyl acrylate rubber having an average particle diameter of 0.05 to 0.2 μm; 0 to 30 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (B-1) comprising 67 to 75 % by weight of an aromatic vinyl compound and 25 to 33 % by weight of a vinyl cyanide compound; 20 to 70 % by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer (B-2) comprising 70 to 75 % by weight of an aromatic vinyl compound and 25 to 30 % by weight of a vinyl cyanide compound; and 0.5 to 10 % by weight of a polyamide resin having a melting temperature (Tm) of 250 °C or higher, wherein the graft copolymer (A-1) and the graft copolymer (A-2) each have a coloring power coverage value of 20 % or more as calculated by Equation 1 below: X = A / S × 100, wherein S represents a content (wt%) of a fusible material (sol) after dissolving the graft copolymers in acetone and performing centrifugation, and A represents a content (wt%) of the vinyl cyanide compound in the fusible material (sol) after dissolving the graft copolymers in acetone and performing centrifugation, wherein the average particle diameter is measured by dynamic light scattering as disclosed in the description, the thermoplastic resin composition being free of a heat resistant styrene-based resin other than the aromatic vinyl compound-vinyl cyanide compound copolymers (B-1) and (B-2), and excluding thermoplastic resin compositions according to Examples 1 to 8 of EP 4 108 722 A1.