How do I edit costumes and alts?

[CitrusJelly]

I'm making a custom PM build for myself and want to make my own colors. I'm not swapping any models, just doing simple recolors.

 

[Panudroid]

To recolor a character, you'll need to edit the textures of the model of the character and replace an existing recolour with that model. So, yeah, even if you want to do simple recolors, you'll need to replace models.