Thermal control coatings (TCCs) regulate the temperature of solid surface through spectrally selective absorption and find wide application in the field of aerospace, aviation, and high-power electronics. Plasma electrolytic oxidation (PEO) has emerged as a versatile technique for fabricating these coatings on lightweight metals, enabling precise temperature regulation by tailoring the solar absorption-emission ratio. This chapter provides a comprehensive review of the principles of thermal control and the modulation of solar absorptivity and infrared emissivity in aluminum, magnesium, and titanium alloys. Mechanisms underlying spectrally selective absorption and emission within PEO coatings are discussed, along with strategies for optimizing their composition, microstructure, and functional properties. Emphasis is placed on innovative approaches, including doping with rare-earth elements, multistep processing, and the integration of composite layers, which enhance thermal stability and durability under extreme operational conditions. Furthermore, emerging trends and future research directions are explored, showcasing the potential of PEO coatings to drive the development of next-generation lightweight materials for high-performance thermal control applications.