There are two kinds of styles for ToggleButtons available in MahApps.Metro.

The default style, available just by placing a ToggleButton control in XAML looks like the default MahApps.Metro button.


Another style, MetroCircleToggleButtonStyle is available by setting the ToggleButton's style to MetroCircleToggleButtonStyle. This style changes the button's background to AccentColorBrush when it is checked. To modify this behaviour, you will have to edit a copy of the control template using Blend.

  <ToggleButton Width="50"
                Margin="0, 10, 0, 0"
                Style="{DynamicResource MetroCircleToggleButtonStyle}">

Using Icons within a Circle ToggleButton