I modified the standard usplash-theme-ubuntu to better fit my 1280x768 widescreen monitor.
I therefor used GIMP to crop the original wallpaper to 1280x768. I then changed the mode to RGB, resized the image to 1024x768 (because that image version is chosen by usplash, just replaced it later), added the progress bar images, reindexed to 256, did some cropping, and ended with:
- A new 1024x768 wallpaper with a squished logo, and
- The two progress bar images.
All three using the same palette (which got a bit mixed up so I changed the colors in the usplash-theme-ubuntu.c source file to represent the "old" colors).
Result after compiling: The logo is shown correctly without any distortions but the text area is dark blue - strange, because it should be black and there is no dark blue in the color palette used by the images. If I change the console resolution to 1024x768 (vga=791) the blue is gone but the console text looks bad. If I use the original theme there is no blue either, so there's definitively a problem with the above procedure.