[1.12.2] Problem with sky/fog rendering

[Meldexun]

Hi there,

I wan't to render custom fog and i noticed that the sky is rendered weirdly. To best describe it i have made screenshots.

So here is the first screenshot where i disabled fog completely. Can anyone explain me why the sky has these 3 color zones?

 

This leads to a problem when i enable fog. Then the middle dark blue zone ignores the fog.

 

So the sky wouldn't be a problem as long as it is be covered by fog. Does anyone know how to fix this? Also i would like to know which class handles the sky rendering.

Thanks for the help.