Railworks America

As you can see in the attachments, the textures have these strange pixels in like rainbow colors. I don't know where that comes from, I have FXAA enabled as well as Anti-Aliasing on Supersampling, I have RW Enhancer, I have a hi-spec gaming setup with a 4k monitor yet still these textures look this pixelated.
Locomotives I have noticed this on:
-Bossman Games Rebuilt Merchant Navy Class (included in the attachments)
-DTG Class 52 Sandstorm livery (also included in the screenshot)
-DTG Pannier Tank
-DTG SR N15 "Sir Lamiel"
-DTG/IHH BR Standard Class 9f
-Just Trains BR Standard Class 7mt
-Smokebox UP FEF-3 (both Overland and black liveries)
I have also noticed that every time I open the .TgPcDx files of the textures the textures get more and more pixelated. I have also tried opening/exporting these .TgPcDx in DXTBmp, but the same issue still occurs. I have ALSO tried resizing the textures to 4k, but that made it worse. Any help is massively appreciated .

In my opinion this is just normal.
Textures in the TS are not suitable to explore them from the immediate vicinity.
This game has it's problems with too large textures.
This is one of the reasons why you get performance problems when you try to populate a station with some highly detailed locos/wagons.