Currently there's a mysterious fix in place for this problem: the PNG file containing the texture was downsampled to 8 bit PNG, and the binary was recompiled using LLVM.
Even so, OS X seems to get confused if there are old versions of RedPill, so before reporting a problem please:
- Delete all old versions.
- Quit System Preferences.
- Empty the trash.
- Install the new version in ~/Library/Screen Savers/
- Run System Preferences.
The above sequence seems to fix the issue for some.
Nevertheless, it would be good if the code could be made more robust, to deal with any depth of PNG file. If anyone has any ideas, please let me know.