Just wanted to to jump in and clarify something about HD6 coding

The reason why it gets brighter when lowering the saturation when using HD6 enbeffect.fx file. Is because he has added a compensation command to help prevent the darkening, that happens when you increase saturation.
CLENB v11-3
float EColorSaturationV2 = 4; // 1.65;
float HCompensateSat = 2; // Compensate for darkening caused by increasing EColorSaturationV2 <------ The compensation command line.
CLENB v11-4
float EColorSaturationV2 = 3.3; // 1.65;
float HCompensateSat = 1.3; // Compensate for darkening caused by increasing EColorSaturationV2 <------ The compensation command line.
And just for the fun of it, my enbeffect settings

JENB + RL + SMAA
// Nighttime Saturation, Red, Green, Blue
float3 dnsatn = float3( 1.45, 1.45, 1.45 );
//
// Daytime Saturation, Red, Green, Blue
float3 dnsatd = float3( 1.7, 1.7, 1.7 );
float EColorSaturationV2 = 2.3; // 1.65;
float HCompensateSat = 1.3; // Compensate for darkening caused by increasing EColorSaturationV2
It made the "lighting" of the colors better, alteast from my point of view
