I just tested in 4.3. I added a default Suzanne Monkey head and changed nothing, then changed the world color. I saw a subtle shift, then did the above solution and it corrected it in all modes. I’ve not been able to replicate this issue – perhaps ask the developers and submit a bug report? See if they notice or have any advice? Here is the link: https://projects.blender.org/blender/blender/wiki/Module:%20Grease%20Pencil
