I like that you see what I did there. I didn’t want to slap it as genders, instead I went for shapes as a broader and more neutral approach instead of the male/female dicotomy, so you can mix whatever you want. There are also no gender based clothing, just slap whatever you want on any character.
As for the outline, the engine will create them automatically! Ideally leave without it, but if you want the engine to properly replace your outline - when the option “Tiny RPG Outline” is on - use #131549 as the colour for it! What I do is run 3 shaders when the option is on: one to remove all #131549, one to add #131549 but without rough corners, then I add ##f7eddc to the faceset only and with corners.