<BundledTheme> currently provides an Inherit option for the BaseTheme attribute, which reads the Dark/Light preference set at the OS level. However, the PrimaryColor and SecondaryColor attributes don't provide such an option.

Add a new value Inherit to the MaterialDesignColors.PrimaryColor and MaterialDesignColors.SecondaryColor enumerations. Using this value will match the accent color configured in Windows Personalization settings.

See the "Accent Color" section on the Personalize Your Colors in Windows page for details.