Hi Keno995,
Button background can be changed by following code:
SolidColorBrush blueBrush = new SolidColorBrush(Windows.UI.Colors.Blue);
button.Background = blueBrush;
Background can be also one of these three brushes:
LinearGradientBrush,
ImageBrush,
SolidColorBrush, image is acceptable.
As you told, you want to switch the color between blue and green, I would suggest you to use a local variable to record the count of your button click event.
--James
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Thanks
MSDN Community Support
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