Conspicuous male coloration is often an honest signal of individual quality. In Dickerson’s collared lizard ( Crotaphytus dickersonae ), males are striking blue, have a black and white collar and have white spots on their bodies. In this study, we investigated whether this extravagant colour pattern is an indicator of male performance in variables related to resource-holding power (bite force, running speed and endurance) and immune condition (cellular response and ectoparasite load). Also, we assessed direct and indirect effects of testosterone levels and body temperature on colour traits. We found that males with bluer skin, and darker and bigger black collars performed better in variables related to resource-holding power. Also, the black colour of the collar was related to immune condition. Blue chroma was positively related to temperature, yet males with bigger and darker black collars had lower body temperatures. Testosterone had minor effects on immune response and colour traits. Our results suggest that multiple colour traits in the Dickerson’s collared lizard may honestly indicate physical and physiological performance.