Joomla's backend has its own light and dark mode. Admin Customizer respects that: by default it does nothing special to dark mode. It leaves Joomla's dark theme in place and derives your brand colors for it automatically, so you get a consistent dark mode for free.

You only need this tab if you want to override specific dark colors, for example to match an exact brand shade.

Custom Dark Mode Colors

Custom Dark Mode Colors – The master switch for this tab.

• No (default) – all dark mode colors are derived automatically from your light mode settings.
• Yes – reveals the color fields below so you can set specific dark colors. Any field you leave empty keeps its automatic color, so you can override just one or two values.

When the switch is on, you can override the following. Every field overrides the automatically derived dark color; leave it empty to keep the automatic value.

General

• Brand Color – the brand color used in dark mode.
• Text on Brand Color – text and icons on top of the dark brand color.
• Link Color – link color in dark mode.

Backend

• Body Background Color – the backend background in dark mode.
• Header Background Color – the backend header in dark mode.
• Sidebar Background Color – the backend sidebar in dark mode.

Login Page

• Body Background Color – the login page background in dark mode.
• Header Background Color – the login header in dark mode.
• Login Box Background Color – the login box in dark mode.
• Sidebar Background Color – the login sidebar in dark mode.

Tip: Start with the switch off and check how the automatic dark mode looks first. In most cases it's already right, and you'll only need to nudge one color.