A unique ReShade preset for Farming Simulator 25 called DeltaFarm Rainy Filter Shaders was created especially to improve gloomy, foggy, and rainy weather.
To provide a more realistic rainy-day farming experience, this preset offers a darker, moodier ambiance with softer lighting, mild fog, lower saturation, and better depth.
(Remember that this is a test version; feel free to ask any questions. When there is a lot of rain and poor field conditions, I like this shader.

Thanks to Litxn