A thermoplastic composition is described herein including a first polyetherimide sulfone having a glass transition temperature of 250 to 290° C., and a second polyetherimide sulfone having a glass transition temperature of 230 to 249° C. The composition has an advantageous combination of optical properties including improved yellowness index, transmission, and haze. A method of manufacturing the thermoplastic composition and articles including the thermoplastic composition are also described. A method for improving the optical properties of a thermoplastic composition is also disclosed, where the method includes melt mixing the first and second polyetherimide sulfones, each having a glass transition temperature as defined herein. The method provides a composition having at least one of improved yellowness, haze, and transmission.