Samples of red sea bream (Pagrus major) were grilled under far-infrared radiation heating. The last step of grilling, namely, carbonization, was analyzed. The temperature and color CIE L∗a∗b∗ at the center of the fish surface were measured during the entire grilling process. The color that developed during the carbonization was analyzed using a kinetic model based on the reduction rate of L∗ values and a computer vision system (CVS). Empirical equations for estimating a∗ and b∗ values were deduced based on the calculated L∗ values. During the carbonization step, the L∗ values of the surfaces decreased slowly. The L∗ values appeared to reach a constant value, the magnitude of which depends on the surface temperature. The color distribution across the entire surface during the grilling process was effectively estimated using the CVS. The effect of surface temperature on carbonization was analyzed by the CVS and successfully visualized using a two-dimensional simulation model.