RGB images acquired on 17 December 2015 taken one hour apart. The right image acquired at UT23h56 shows a relatively blue region (indicated by the white rectangle) at dawn. The same area was observed in a sequence acquired one hour later (on 18 December 2015, UT 00:56) and it shows a color indistinguishable from that of the average Wosret region. The bluing at dawn is periodic and observed in other sequences in December 2015 but also in June 2015, as shown in the top insert of the image on the right side.