The appearance of muted parts isn’t very clear. Muted parts have a bright grey background, actually brighter than a part’s default colour. Over a dark background this doesn’t look very muted to me. The only way you can tell it’s muted is when looking at the part’s caption. Suggestion: Make muted parts 50% semi-transparent so you can tell at a glance which parts are muted and which are not.
Shared copies are not rendered clearly enough either. The icon at the right end of a part should stick out more. It can be very frustrating when you edit a part you supposed to be a real copy but turns out to be a shadow copy.