Color-temperature evolution for both observed TRAPPIST-1 flare with MuSCAT 2. In the left column, all temperature evolutions for the different filter ratio functions R_j(T_eff) are shown, and in the right column, the same is done for flare 2. The orange line indicates the model drawn from the best-fit to the flare flux profile, with respective model uncertainties represented by the orange shaded areas.