DOWNLOAD AND INSTALLE RESHADE https://reshade.me/component/content/featured?Itemid=101

Installation
Download the installer on the main page.
Install by selecting the game's executable (if you are not sure which API to select, check the "Games" section of this site)
The example shader repo is never a bad choice, it supplies you with a set of new and old shaders ported to new format.
The file structure in the game folder (where the game's exe is) is now the following:
ReShade DLL (can be dxgi.dll, d3d9.dll, opengl32.dll)
Folder "reshade-shaders" with subfolders "Shaders" and "Textures"

This ReShade is designed to give the country in RDR2 the proper look depending on the climate. Plains, and droughts will showcase dying grasses, while marshes and swamps will showcase lush vibrance. This is a Film style noir, wild west ReShade. It looks like this for a reason. There is a lot more clarity to the picture, and the yellowish green film layer that was covering the screen, is now removed.

PRESS "HOME" WHEN IN GAME TO SELECT THE WILD WEST.INI PRESET FOR RESHADE, PRESS SELECT TO ENSURE YOU'VE CHOSEN IT.

ENJOY ;)