This is the image with no indirect lighting.
This is the image with indirect lighting. (Please notice saturation went just sh*tty)
And this is the image with indirect lighting saturation zero (Please notice it is just same)
So indirect saturation is not working.
And please do not ask if I built my light or something.
It was also not working UDK which I reported it 7 months ago.
I have a suspicision UDK and Unreal 4 has same code with indirect lighting saturation part.