^ I don't understand your 4/13 chance remark. The player is always going to be wearing the formal attire in that scene because that is the only armless model in the game.
Here is how the tinting works... For the normal default formal attire the tint colors are coded directly into the model mesh. Only three things are able to be tinted: the jacket, the sash, and the metallic trim. The wardrobe has a default option, and it just loads the basic model mesh. For the Trespasser scene, we have the armless model mesh with that same tint color information coded directly into the model mesh.
So, lets bring in the wardrobe tints. There are three additional tints provided by the wardrobe. What these do is overlay the formal attire model with different materials, just like the tint table does. The file lists the different materials -- primary cloth, secondary cloth, leather, metal -- and points to the item to be tinted, in this case the formal attire. There are NOT different tints for each race and gender. Those same tints cover everyone, just as the same textures cover everyone. The only things that exist with different variations for each race and gender are the model meshes. So, whatever extra stuff you do with the tints, you only need to edit those three additional files, not 32.
If I wanted to alter one of the tints to be all light colors -- silk, cotton, dragon, silverite -- I can just change out the materials in one file and make a mod with those changes. Everyone of all races and genders would be able to use the mod. It's not the same as the Skyhold attire (aka PJ) mods that were released. Those edit the textures directly, and each race and gender has their own variation, which is why selection is restrictive and limited.
EquipItemAppearance : [ItemAppearance] da3/equipment/appearances/armors/item_app_armor_formal_wear
For the armless formal attire, the problem comes in that there is NOT a corresponding item_app_armor_formal_wear_armless, because that is not an actual item in the game you can have. You can have a standard formal attire item, which is what is in your inventory at the ball during Wicked Eyes and Wicked Hearts.
Now, all of these tint files only have one EquipItemAppearance assignment listed. I can only assume that in order for them to have had the wardrobe tint the armless version as well, the tint file would have needed to be altered with an additional EquipItemAppearance. But as mentioned, there is no item_app file for the armless version. The only thing that exists for the armless version is the model mesh, which is what we see in that scene.
Now, you can edit the tint colors on both the standard and armless formal model meshes and make mods. I have done this and was successful with the standard version. But I have yet to test the armless version because I don't want to play Trespasser again.
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So... now that I've written all this out I can see why it might have been problematic for them to have the wardrobe tint the armless version. It's still a bummer though. As far as I know, the formal attire texture mods still cause an infinite loading screen when you attempt to load Trespasser. If this can eventually be fixed on the Mod Maker or Mod Manager side of things we should be all set with our armless version color-wise.