I always have three vaults open all day long: Film, Food and Main.
I find it simpler to use the same theme for all my vaults.
But when I Alt-Tab through my open windows, or just look at my taskbar, it’s tricky to distinguish between the three vaults.
Solution: I created a css in two of my vaults where I added a splach of colour to the top title bar and the left menu bg. As you can see from the screenshot, the colours also show up in the taskbar pop-ups, making it easy to select the correct vault.
I really can’t say.
I created one new css for each vault, and enabled it in each vault.
Maybe it has to do with Obsidian settings?
Under Obsidian Options > Appearance I have
Base color scheme: Dark
Accent color: purple
Themes: default
Window Frame style: obsidian frame
Or maybe the “titlebar” is part of the Homepage plugin, rather than being native to Obsidian?