How to detect the dark or light theme in Windows Phone 7

If the user of the Windows Phone 7 device switches from the default dark theme to the light theme, how do you detect which one is in use? In the MSDN article Theme Resources for Windows Phone, there are two interesting resource keys that you can query. These are the PhoneDarkThemeVisibility and PhoneLightThemeVisibility keys. So based on these we can determine if we should use a dark or light background image in our application, like so:

var isLightTheme = (Visibility)Application.Current.Resources["PhoneLightThemeVisibility"];
var imageBrush = new ImageBrush();
var imageUri = new Uri(isLightTheme == Visibility.Visible ? "background-light.jpg" : "background-dark.jpg", UriKind.Relative);
imageBrush.ImageSource = new System.Windows.Media.Imaging.BitmapImage(imageUri);
MainPanorama.Background = imageBrush;

Windows Phone 7 Theme Colors

The Windows Phone 7 has two different background color modes; dark or light. In addition, there are ten accent colors to choose from.

There’s currently no simple way of detecting which theme and accent color that the user has selected his or her device. However, since the colors of the current theme is injected into to applications resources, one can at least read out the various colors from there.

The background color can be determined using this piece of code:

Color backgroundColor = (Color)Application.Current.Resources["PhoneBackgroundColor"];

And in a similar fashion the foreground and accent colors can be determined like this:

Color foregroundColor = (Color)Application.Current.Resources["PhoneForegroundColor"];
Color accentColor = (Color)Application.Current.Resources["PhoneAccentColor"];

All the various resource names are described here; Theme Resources for Windows Phone.

Theme	Background Color Value	Foreground Color Value
Dark	#FF000000	#FFFFFFFF
Light	#FFFFFFFF	#DE000000

Accent color	Value
	#FFFF0097
	#FFA200FF
	#FF00ABA9
	#FF8CBF26
	#FFA05000
	#FFE671B8
	#FFF09609
	#FF1BA1E2
	#FFE51400
	#FF339933

Upcoming books on Windows Phone 7 development

Reading a book about Windows Phone 7 development is a great way to get you started on developing on the Windows Phone 7. Here is a list of known upcoming books on the subject.

	Beginning Windows Phone 7 Development by Henry Lee Published by Apress. More info
	Pro Windows Phone 7 Development by Rob Cameron Published by Apress More info
	Windows Phone 7 Game Development by Adam Dawes Published by Apress More info
	Windows Phone 7 Unleashed by Daniel Vaughan Published by SAMS
	Learning Windows Phone Programming By Yochay Kiriaty, Jaime Rodriguez Published by O’Reilly More info
	Programming Windows Phone 7 by Charles Petzold Published by Microsoft Press More info
	Windows Phone 7 Application Development (Developer's Library) by Corey Schuman Published by Addison-Wesley Professional
	XNA Game Studio 4.0 Programming: Developing for Windows Phone and Xbox Live (Developer's Library) by Tom Miller, Dean Johnson Published by Addison-Wesley Professional
	Beginning Windows Phone 7 Application Development: Building Windows Phone Applications Using Silverlight and XNA by Nick Lecrenski, Karli Watson, Robert Fonseca-Ensor Published by Wrox
	Professional Windows Phone 7 Game Development: Creating Games using XNA Game Studio 4 by Chris G.Williams, George W. Clingerman Published by Wrox