There appear to be some places in Houdini where Red is Blue and vice versa.
See the scene and screenshots, this was tested under Hou11.0.581/Win64, 11.0.834/Win64, 11.1.118/Win64 and 11.1.206/Win32.
1) using 24-bit TGAs as textures - this only happens in OGL (tested with both NVidia & ATI cards), Mantra renders them properly, COP/File reads them correctly as well;
2) COP ChannelCopy - see pictures 2 and 3, and examples in /img/comp1 … I don't know if this is related somehow to problem #1, ChanCopy actually has the channels in its menu listed in “reversed” order - C.b, C.g, C.r (so is this a bug or just a typo in the interface?);
3) Python - CopNode.allPixels(“C”, “r”) returns the blue pixels, “b” returns the reds - see example Python COP filter in the scene;
#1 seems like a bug clearly, but what about ChannelCopy? I seem to remember that it works this way since Hou9. But CopNode has this quirk as well. So maybe these are related problems.