RangeSlider.xaml

<views:RangeSlider
                x:Name="RangeSlider"
                MaximumValue="10"
                MinimumValue="-10"
                LowerValue="-10"
                UpperValue="10"
                ValueLabelStringFormat="{StaticResource CustomValueLabeStringFormat}"
                LowerValueLabelStyle="{StaticResource CustomLowerValueLabelStyle}"
                UpperValueLabelStyle="{StaticResource CustomUpperValueLabelStyle}"
                ThumbSize="{Binding Value, Source={x:Reference ThumbSizeSlider}}"
                ThumbColor="{Binding SelectedItem, Source={x:Reference ThumbColorPicker}}"
                LowerThumbColor="{Binding SelectedItem, Source={x:Reference LowerThumbColorPicker}}"
                UpperThumbColor="{Binding SelectedItem, Source={x:Reference UpperThumbColorPicker}}"
                ThumbBorderColor="{Binding SelectedItem, Source={x:Reference ThumbBorderColorPicker}}"
                LowerThumbBorderColor="{Binding SelectedItem, Source={x:Reference LowerThumbBorderColorPicker}}"
                UpperThumbBorderColor="{Binding SelectedItem, Source={x:Reference UpperThumbBorderColorPicker}}"
                TrackSize="{Binding Value, Source={x:Reference TrackSizeSlider}}"
                TrackColor="{Binding SelectedItem, Source={x:Reference TrackColorPicker}}"
                TrackHighlightColor="{Binding SelectedItem, Source={x:Reference TrackHighlightColorPicker}}"
                TrackBorderColor="{Binding SelectedItem, Source={x:Reference TrackBorderColorPicker}}"
                TrackHighlightBorderColor="{Binding SelectedItem, Source={x:Reference TrackHighlightBorderColorPicker}}"
                IsEnabled="{Binding IsToggled, Source={x:Reference IsEnabledSwitch}}"
                ValueLabelSpacing="{Binding Value, Source={x:Reference ValueLabelSpacingSlider}}">

                <views:RangeSlider.LowerThumbView>
                    <Label Text="L" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" IsVisible="{Binding IsToggled, Source={x:Reference LowerThumbViewSwitch}}" />
                </views:RangeSlider.LowerThumbView>

                <views:RangeSlider.UpperThumbView>
                    <Label Text="U" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" IsVisible="{Binding IsToggled, Source={x:Reference UpperThumbViewSwitch}}" />
                </views:RangeSlider.UpperThumbView>
            </views:RangeSlider>