A frustrating irk of Obsidian is constantly toggling between reading and editing modes – either trying to edit while in Reading view, or forgetting to switch to Reading mode when just browsing. (Visually conflicting icons certainly don’t help.)
To help with that, I created a little plugin to help me discern at a glance between Reading view, Live Preview and Source by assigning a distinct accent color for each view:
Try it out:

