current game version: 1.5.0.0.3 (all mods confirmed working)
Head over to https://reshade.me/ and download the latest ReShade. (With or without Add-ons is fine.)
Start the installer (ReShade_Setup_6.0.1.exe file, in the case of ReShade version 6.0.1).
Follow the steps below:
When you start the installer, wait until TheRanchOfRivershine appears in the list and select it.
Pick "DirectX 10/11/12" from the list in the next screen.
If you have a preset (.ini file) already, pick "Browse" and choose it. The list of effects to install will update itself. Otherwise, pick any from the list that you would like.
Once in the game, follow the tutorial displayed on the screen to make yourself familiar with ReShade. You can then freely edit and adjust any presets you have, or even make your own and share their .ini files with the community.
If at any point you want to remove ReShade or add effects that aren't already installed, just re-run the installer.
This preset is inspired by the color scheme of old beta/alpha visuals of the game. It has the following effects:
color grading
bloom
lens flare
eye adaption
Download here and extract into folder of your choice.