Can you please show me a link to which eye textures did you want to add to your game?
These eyes are made to be used for presets and not in game.
They can't work in game, unless your using them on your preset.
The reason why they can't work is because they are, as you can see, already colored and edited.
Eyes for Feral Heart in game need to have transparent part so when adding your color, It is seen.
Here are some very pretty eyes for your game that you could use:
- https://mushyeyeballs.deviantart.com/art/FeralHeart-Eye-Textures-by-Circusfreak-460446943
- https://ki-cortana.deviantart.com/art/KI-Cortana-s-Modified-Eyes-for-Feral-Heart-407964200
- https://shay-wolf.deviantart.com/art/FeralHeart-Eye-Mod-485674790