How do I edit the style of a controls flyout in blend

Question

I need to edit the design of a button-flyout but I can't find a reference to the flyout. In the Blend Object-Explorer I dont find any flyout at all:

So what's the trick to access the flyout. I saw there is a special TimePickerFlyout class https://msdn.microsoft.com/library/windows/apps/windows.ui.xaml.controls.timepickerflyout.aspx in UWP, but if I search for it inside my template or the project code, the only thing I find is TimePickerFlyoutButtonStyle in the Templates Ressources which, in my understanding, contains the storyboard information for the Buttons appearance.

<StackPanel.Resources>
    <Style x:Key="TimePickerFlyoutButtonStyle" TargetType="Button">
        <Setter Property="UseSystemFocusVisuals" Value="False"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Grid Background="{TemplateBinding Background}">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="PointerOver">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlPageBackgroundAltMediumBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Pressed">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseMediumLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="FocusStates">
                                <VisualState x:Name="Focused">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightListAccentLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltBaseHighBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Unfocused"/>
                                <VisualState x:Name="PointerFocused"/>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <ContentPresenter x:Name="ContentPresenter" AutomationProperties.AccessibilityView="Raw" BorderBrush="{ThemeResource SystemControlForegroundBaseMediumLowBrush}" BorderThickness="2" Background="{ThemeResource SystemControlBackgroundAltMediumLowBrush}" Content="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</StackPanel.Resources>

Answer 1

I did the following to change the TimePickerFlyout's background colour and the size of the buttons on its footer.

1. Navigate to C:\Program Files (x86)\Windows Kits\10\DesignTime\CommonConfiguration\Neutral\UAP\10.0.10240.0\Generic Note this may change depending on your SDK version

2. Open the generic.xaml file

3. Copy the TargetType="TimePickerFlyoutPresenter" section to your Assets\ControlStyles.xaml

Here is the xaml from the generic.xaml file...

<!-- Default style for Windows.UI.Xaml.Controls.TimePickerFlyoutPresenter -->
<Style TargetType="TimePickerFlyoutPresenter">
    <Setter Property="Width" Value="242" />
    <Setter Property="MinWidth" Value="242" />
    <Setter Property="MaxHeight" Value="396" />
    <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
    <Setter Property="FontWeight" Value="Normal" />
    <Setter Property="IsTabStop" Value="False" />
    <Setter Property="Background" Value="{ThemeResource SystemControlBackgroundChromeMediumLowBrush}" />
    <Setter Property="AutomationProperties.AutomationId" Value="TimePickerFlyoutPresenter" />
    <Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundTransparentBrush}" />
    <Setter Property="BorderThickness" Value="{ThemeResource DateTimeFlyoutBorderThickness}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TimePickerFlyoutPresenter">
                <Border x:Name="Background"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        MaxHeight="396">
                    <Grid x:Name="ContentPanel">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*" />
                            <RowDefinition Height="44" />
                        </Grid.RowDefinitions>

                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*" x:Name="FirstPickerHostColumn" />
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="*" x:Name="SecondPickerHostColumn" />
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="*" x:Name="ThirdPickerHostColumn" />
                            </Grid.ColumnDefinitions>

                            <Rectangle x:Name="HighlightRect" Fill="{ThemeResource SystemControlHighlightListAccentLowBrush}" Grid.Column="0" Grid.ColumnSpan="5" VerticalAlignment="Center" Height="44" />

                            <Border x:Name="FirstPickerHost" Grid.Column="0" />
                            <Rectangle x:Name="FirstPickerSpacing" Fill="{ThemeResource SystemControlForegroundBaseLowBrush}" HorizontalAlignment="Center" Width="2" Grid.Column="1" />
                            <Border x:Name="SecondPickerHost" Grid.Column="2" />
                            <Rectangle x:Name="SecondPickerSpacing" Fill="{ThemeResource SystemControlForegroundBaseLowBrush}" HorizontalAlignment="Center" Width="2" Grid.Column="3" />
                            <Border x:Name="ThirdPickerHost" Grid.Column="4" />
                        </Grid>

                        <Grid Grid.Row="1" >
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <Rectangle Height="2" VerticalAlignment="Top" Fill="{ThemeResource SystemControlForegroundBaseLowBrush}" Grid.ColumnSpan="2" />

                            <Button x:Name="AcceptButton" Grid.Column="0" Content="&#xE8FB;" FontFamily="{ThemeResource SymbolThemeFontFamily}" FontSize="16" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Style="{StaticResource DateTimePickerFlyoutButtonStyle}" Margin="0,2,0,0" />
                            <Button x:Name="DismissButton" Grid.Column="1" Content="&#xE711;" FontFamily="{ThemeResource SymbolThemeFontFamily}" FontSize="16" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Style="{StaticResource DateTimePickerFlyoutButtonStyle}" Margin="0,2,0,0" />
                        </Grid>
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>