Obsidian 0.16+ introduces a revamped window frame for the new Tabs feature. With Minimal Theme Settings you can now activate the Colorful frame toggle (also available as a hotkey). This is especially useful if you use multiple Obsidian vaults and would like to color-code them. The color is automatically derived from your preference in the new Accent color in Obsidian Appearance settings, but you can also customize it further via Style Settings plugin.
Light mode
Dark mode