Invalid pixels have transparency set to 100% yet they are not black. These pixels are inverting background color if used on cursors. They should not be present in normal images.
1212
Invert
1213
Invert color of each pixel (subtract its color from white).
Inverse les couleurs de chaque pixel. soustrait sa couleur du blanc.
1214
Invert colors
Inverse les couleurs
1215
It is recommended to save and close all other documents and restart the program.