You may have messed up your folders 0 & 1 when experimenting for those interface files(?). I'd reinstall the GP arch and ensure you are using the colour paletters for Cossacks I ( the ones I put in the 'FOR COSSACKS" folder). Make sure you dont overwrite the existing one's, but delete the one's in your GP arch and then copy the ones from the FOR COSSACKS folder.
Clean install: Extract GPArch from "5_GpArch.rar" to path "C:\" [check]
Delete folder "0" and "1"and replace with the same folders from "FOR COSSACKS" [check]
Use MegaPack with default settings and Palette 1 [check]
Blurry result [check check]
I attached the original file "AKABR.gp", from the GOG edition, that I'm using to test the BMP to GP conversion. Can you please test if you can extract and convert it again with success, using the steps you mentioned? I would be very appreciated.
Yes this is just a test. I was getting this results with the interface files and I didn't know if it was a specific problem with those files, so I tested the common GP files (buildings and units).
Also im assuming that you are testing to repack your interface files later, but if you aren't and you are trying to repack buildings, mind the national colour, the way you are doing it, its all gonna be blue in game without fixing it before repacking.
use mode "Simple packing image" with the proviso that the top and left Pictures have a background
With "Simple packing image" I get a black image result. With "Simple packing image" and the pure green background I get the same blurry result.