The advantages achieved in two-color optical pyrometry using wide-band gap semiconductors (e.g., silicon carbide, gallium arsenide) and silicon-based photosensors for short- and long-wavelength light detection, respectively, are demonstrated here. Spectral responsivities of Si-, SiC-, and GaN-based photodiodes are used to evaluate the performances of a simple ratio pyrometer. Compared to conventional near-infrared ratio pyrometers, it is shown that high-energy photon detection is able to reduce temperature measurement errors—mainly induced by spectral variation of the target emissivity—by more than 1 order of magnitude and allows increased output dynamics of the pyrometer of up to 4 orders of magnitude.