Weird dark border on sprite

[boney]

Hey all! I've just recently started spriting custom items for Ragnarok and got an issue that's hella annoying.

So, what's happening is that I'm making a mid costume that's an eye. And as every blinking/colored eyes, the sprite must blend in perfectly so it doesn't look weird.

My problem is that mine doesn't blend.

Actually, it does blend outside of the game (as in Act Editor, photoshop, aseprite, and such). When I equip it in-game, boom, there's a black border which makes the eyes look like those weird sleeping masks.

I'm not sure if I'm exporting it wrongly, if the SPRConview is messing with me, or I'm missing something when adding it ingame. I basically followed this guide to a tee (except I'm using Act Editor and not actOR).

 

This is the sprite in Act Editor

 

This is the sprite ingame. Can you see the dark border? It's especially visible at the "nose bridge"/lower section.

This is a costume from the Original RO with essencially the same skin colored around the eyes, but can you notice how it has a clear border, barely noticeable?

So yeah, that's the issue. I'm losing my mind trying to figure out why this is happening.

If anyone could shed me some light, I would greatly appreciate it!

Thanks!