Continuum images at 08:57 UT (left) and 11:53 UT (right) superimposed with the white-light flare kernels derived from 30-mintime series of continuum images covering the X2.2 and X9.3 flares (see scale bar for the temporal evolution). The blue-colored overlays represent the 2D frequency distribution of pixels exhibiting strong UV excess brightenings with respect to the pre-flare phase. The boxes mark the locations of penumbral decay (A – C) and umbral strengthening (D).