The button's background will be White and foreground will be Black in the Light theme while Black and White in the Dark theme. Here is an example of a simple theme dictionary: You can also write your own theme dictionary that specifies colors for each theme.

Or you can use SystemControlBackgroundAccentBrush which will reflect the Accent color chosen in Settings app. You can use predefined XAML theme resources, for example this Border's background color will be #FFFFFFFF in Light theme and #FF000000 in Dark theme.

To reflect theme and accent color set in Settings app specifying custom color for some element, you have to use ThemeResource. įor color customization UWPs usually use Accent color specified by user in Settings > Personalization > Colors too. You can also set the theme of any specific FrameworkElement which is set to ElementTheme.Default by default so it inherits the theme from its parent. On older Windows 10 desktop versions it'll be Light. If you don't set the RequestedTheme property, it will reflect the theme set in Settings > Personalization > Colors on any W10 Mobile device or W10 PC running Anniversary update and newer version. You can specify your app's theme in the App.xaml by setting the RequestedTheme property to either one of the values (it is set to Light by default) or in in App constructor using RequestedTheme = ApplicationTheme.Light (changing it anywhere later will cause an exception to be thrown). By default, the UWP apps support two themes - Light and Dark.

Make your own theme windows 10