switchSchemeColor property

Defines which Theme based ColorScheme based color the Switch and SwitchListTile use as base themed color.

When not using sub-themes, the color defaults to ThemeData.colorScheme.secondary color that is used as FlexColorScheme's default for ThemeData toggleableActiveColor, as long as still needed.

The ThemeData property toggleableActiveColor is being deprecated https://github.com/flutter/flutter/pull/95870. A future change for FlexColorScheme will be to see if it will be possible to continue to offer ThemeData.colorScheme.secondary as default color when not opting in on using the component sub-themes. Currently the default is already ColorScheme.secondary when not opting in on using sub-themes, matching the old Material 2 design standard.

When you opt-in on using opinionated sub-themes, the default color is ColorScheme.primary. The opinionated themes uses a style that matches M3 color design based themes, and in it switches and toggles are mostly primary color based. In M3 color design, the secondary color is a poor choice for switches and toggles and it is therefore not used as default color, since it does not look nice with M3 based ColorSchemes, created eg using M3 color seeding. If you use a custom M3 color design where secondary color is still prominent, you can of course still use it.