Basics of Theme Editing

Hi all, so Im trying to make a little theme here (just for fun really, I think the v5 design is great) - problem: ive been using the "small layout" as default...and id like to walter it for my finishing touch...but when i change the number sequence in rtconfig, nothing happens. What could it be? When i make tcp "default" the "mute" button disappears and maybe i cocked it up making new icons? best