Texture compression(?)

[Ginnunga]

Hey there I got a question. First of all I'm completely naive when it comes to all this. This might have been answered before but I could not find anything.
So I am working on some custom armor designs. They are just simple Loose Files atm. I have used the vanilla textures files as templates, and painted over them in photoshop. As you can see in the comparison image, a lot of shading has been lost and some pixles have been replaced with black and grey etc. (I'm guessing it's a compression issue, since I tried to run my png file through an online compressor. It did give me a different result in game, but not for the better. Worse actually.)
I assume there is something else I need to do with my files, but as I said I'm cluless. Any insight would be much appreciated.

[King of Worms]

Try using a png file which has not been processed by online png compression. That step is unnecessary anyway

Edit: what bit depth u using? If 64, change to 32

[King of Worms]

Thinking about it, just post those boots loose file here, I will download and check it.

[Ginnunga]

Try using a png file which has not been processed by online png compression. That step is unnecessary anyway

Edit: what bit depth u using? If 64, change to 32

Yeah I do. Just tried it once. It's 32bit.
251_0-0 (Male Nord)
https://i.imgur.com/kCTsOku.png

[King of Worms]

It appears all right to me.
Do you have "Compress modded textures" enabled? Try disabling it. Its in the Advanced options / Enhancements

If this doesnt help, the problem might be cause by the fact its used as a loosefile. Packing it in the DFMOD and selecting proper attributes in Unity inspector might solve the issue.