how do you apply the skin colors in shadow lords or cant you?
What do you mean? Like the mimic skins? Or regular?
Mimics don’t appear to be available in Shadow Lords.
Saves on unnecessary confusion.
normal skins and customisation items, stuff like that.
You mean alternate colors and accessories?
yeah
I haven’t got around to using the mode yet, but I have seen people using them in play throughs. I think you have finish Kim and Jago first
Unless you are playing the mode for the first time (in this case you have to beat the tutorial first), you should be able to choose your colors and accessories when picking your teams.
cool stuff still on my first play through
You select them like you would in any other mode.
Yes you can use all colors accessories a fter competing once
If you’re still on your first run, might as well just keep on plowing through as you are. You can worry about looking fancy on your second run. 
U just need to go main menu and start a new game. Then u can choose ur team as u like and apply the colors/acessories. Without losing any achievements.