In Photoshop command H is the keyword function to remove the lasso selection when you try to colour. I don’t know if there is something similar with Clip Studio Paint. It is distracting when you see the selection boundaries and trying to colour something. I want the selection boundaries hidden when I paint something on screen. I hope I’m making sense, it’s hard to describe. I use Clip Studio Paint because I own it and can’t afford Adobe subscriptions. Any advice is greatly appreciated