QuickLook/QuickLook.Common/Styles/ScrollBarStyleDictionary.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <SolidColorBrush x:Key="StandardBorderBrush" Color="#888" />
    <SolidColorBrush x:Key="StandardBackgroundBrush" Color="#FFF" />
    <SolidColorBrush x:Key="HoverBorderBrush" Color="#DDD" />
    <SolidColorBrush x:Key="SelectedBackgroundBrush" Color="Gray" />
    <SolidColorBrush x:Key="SelectedForegroundBrush" Color="White" />
    <SolidColorBrush x:Key="DisabledForegroundBrush" Color="#888" />
    <SolidColorBrush x:Key="NormalBrush" Color="#888" />
    <SolidColorBrush x:Key="NormalBorderBrush" Color="#888" />
    <SolidColorBrush x:Key="HorizontalNormalBrush" Color="#888" />
    <SolidColorBrush x:Key="HorizontalNormalBorderBrush" Color="#888" />
    <LinearGradientBrush x:Key="StandardBrush" StartPoint="0,0" EndPoint="0,1">
        <GradientBrush.GradientStops>
            <GradientStopCollection>
                <GradientStop Offset="0.0" Color="#FFF" />
                <GradientStop Offset="1.0" Color="#CCC" />
            </GradientStopCollection>
        </GradientBrush.GradientStops>
    </LinearGradientBrush>
    <SolidColorBrush x:Key="GlyphBrush" Color="#444" />
    <LinearGradientBrush x:Key="PressedBrush" StartPoint="0,0" EndPoint="0,1">
        <GradientBrush.GradientStops>
            <GradientStopCollection>
                <GradientStop Offset="0.0" Color="#BBB" />
                <GradientStop Offset="0.1" Color="#EEE" />
                <GradientStop Offset="0.9" Color="#EEE" />
                <GradientStop Offset="1.0" Color="#FFF" />
            </GradientStopCollection>
        </GradientBrush.GradientStops>
    </LinearGradientBrush>

    <!--  SrollViewer ScrollBar Repeat Buttons (at each end)  -->
    <Style x:Key="ScrollBarLineButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="OverridesDefaultStyle" Value="true" />
        <Setter Property="Focusable" Value="false" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <Border x:Name="Border"
                            Margin="1"
                            Background="{StaticResource NormalBrush}"
                            BorderBrush="{StaticResource NormalBorderBrush}"
                            BorderThickness="0.25"
                            CornerRadius="2">
                        <Path HorizontalAlignment="Center"
                              VerticalAlignment="Center"
                              Data="{Binding Path=Content, RelativeSource={RelativeSource TemplatedParent}}"
                              Fill="{StaticResource GlyphBrush}" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter TargetName="Border" Property="Background" Value="{StaticResource PressedBrush}" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <!--
        SrollViewer ScrollBar Repeat Buttons (The part in the middle,
        not the thumb the long area between the buttons )
    -->
    <Style x:Key="ScrollBarPageButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="OverridesDefaultStyle" Value="true" />
        <Setter Property="IsTabStop" Value="false" />
        <Setter Property="Focusable" Value="false" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <Border Background="Transparent" />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <!--
        ScrollViewer ScrollBar Thumb, that part that can be dragged
        up/down or left/right Buttons
    -->
    <Style x:Key="ScrollBarThumb" TargetType="{x:Type Thumb}">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="OverridesDefaultStyle" Value="true" />
        <Setter Property="IsTabStop" Value="false" />
        <Setter Property="Focusable" Value="false" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Thumb}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="0.25"
                            CornerRadius="2" />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <!--  VerticalScrollBar Template using the previously created Templates  -->
    <ControlTemplate x:Key="VerticalScrollBar" TargetType="{x:Type ScrollBar}">
        <Grid Width="13">
            <Grid.RowDefinitions>
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Border Grid.RowSpan="3"
                    Background="Transparent"
                    CornerRadius="2" />
            <Track x:Name="PART_Track"
                   Grid.Row="0"
                   IsDirectionReversed="true">
                <Track.DecreaseRepeatButton>
                    <RepeatButton Command="ScrollBar.PageUpCommand" Style="{StaticResource ScrollBarPageButton}" />
                </Track.DecreaseRepeatButton>
                <Track.Thumb>
                    <Thumb Margin="1,0"
                           Background="{StaticResource HorizontalNormalBrush}"
                           BorderBrush="{StaticResource HorizontalNormalBorderBrush}"
                           Style="{StaticResource ScrollBarThumb}" />
                </Track.Thumb>
                <Track.IncreaseRepeatButton>
                    <RepeatButton Command="ScrollBar.PageDownCommand" Style="{StaticResource ScrollBarPageButton}" />
                </Track.IncreaseRepeatButton>
            </Track>
        </Grid>
    </ControlTemplate>
    <!--  HorizontalScrollBar Template using the previously created Templates  -->
    <ControlTemplate x:Key="HorizontalScrollBar" TargetType="{x:Type ScrollBar}">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>
            <Border Grid.ColumnSpan="3"
                    Background="Transparent"
                    CornerRadius="2" />
            <Track x:Name="PART_Track"
                   Grid.Column="0"
                   IsDirectionReversed="False">
                <Track.DecreaseRepeatButton>
                    <RepeatButton Command="ScrollBar.PageLeftCommand" Style="{StaticResource ScrollBarPageButton}" />
                </Track.DecreaseRepeatButton>
                <Track.Thumb>
                    <Thumb Margin="0,2"
                           Background="{StaticResource NormalBrush}"
                           BorderBrush="{StaticResource NormalBorderBrush}"
                           Style="{StaticResource ScrollBarThumb}" />
                </Track.Thumb>
                <Track.IncreaseRepeatButton>
                    <RepeatButton Command="ScrollBar.PageRightCommand" Style="{StaticResource ScrollBarPageButton}" />
                </Track.IncreaseRepeatButton>
            </Track>
        </Grid>
    </ControlTemplate>
    <!--  Style for overall  ScrollBar  -->
    <Style x:Key="{x:Type ScrollBar}" TargetType="{x:Type ScrollBar}">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="OverridesDefaultStyle" Value="true" />
        <Style.Triggers>
            <Trigger Property="Orientation" Value="Horizontal">
                <Setter Property="Width" Value="Auto" />
                <Setter Property="Height" Value="15" />
                <Setter Property="Template" Value="{StaticResource HorizontalScrollBar}" />
            </Trigger>
            <Trigger Property="Orientation" Value="Vertical">
                <Setter Property="Width" Value="13" />
                <Setter Property="Height" Value="Auto" />
                <Setter Property="Template" Value="{StaticResource VerticalScrollBar}" />
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>