This mod restores the Bloodly Screen Effect when hitting enemies from a close distance. Also has a seperate download to fully remove the blood effect (check below the video for a brief explaination)

Here's a showcase of the Restored Blood effect:

Why is there a Removal Option?
See, Overkill didn't exactly remove the effect properly. You are still able to very slightly see the blood effect if your monitor is at a high contrast. Imagine if the opacity was set at 25 instead of 0.
What's the difference between this and Undeadsewers version?
This mod only effects the actual .effect file rather than doing lua magic. Think of this mod as a direct restoration/removal, plus this also has future proofing too!

Extract one file of your choosing into mod_overrides