- Don't use BGRA format at all. It doesn't work with non-typical cases (i.e. with srgb or compressed textures) and also casues artifacts on some android devices. I kept the extension in central settings, but it probably won't be used.
- Use sRGB texture format when advanced lighting is enabled. This makes it closer to the original OpenGL renderer and also avoids to have even more #ifdef's for sRGB conversions.
- Keep RGBA textures for non-advanced lighting to make it simpler.
Now advanced lighting in GLES looks almost the same as in OpenGL 3.x (without shadows/GI)