New Skin - What am I doing wrong?

Hello.
I would like to create my own skin for the LMP2 Oreca 03 with gimp. In the game I can see my skin in the background, but the old logos are shadowy (for example the Judd Power logo). I don't see these logos in Gimp and I can't find a level in the template where I can deactivate them. What am I doing wrong?
Greetings Michael