If you modify the color palette, the bitmap is reversed.

If you modify the color palette, you can reverse the color of a monochrome bitmap file.
Http://www.delphi2007.net/DelphiMultimedia/html/delphi_20060925090610294.html
How can I modify the color palette and change the color palette from black to white and from white to black? The tall man can use Delphi to write a short example. Program? Urgent

Parse the R, G, and B. Use pixels [x] [y] of canvas, and use the getrvalue, getgvalue, and getbvalue functions. Then, subtract the value 255, that is:
Pixels [x] [Y] = getrvalue (pixels [x] [Y])-255;
......

Reverse the value of the color palette.

The RGB component of each color value in the color palette is reduced by 255.