You can override the standard Windows highlight an selection colors on a thumbnail view, e.g. a vire with blue selection and light blue hovering:

Use this code in the Fred config:

<TabItem Name="PagesTab" Header="Pages">

...

  <l:ShellResultView Style="{DynamicResource ShellResultView}" Grid.Row="1" Name="ResultView" l:DragDropHelper.IsDragSource="true" l:ShellData.IsRegistered="True" DirectoryStyleName="Thumbnails" LeftDoubleClickCommandParameter="OnPageDoubleClick" RightMouseClickCommandParameter="ShowPageNavigatorPopup" SearchCriteriaSource="{Binding Path=(l:ShellData.ShellData).SearchCriteria[Search], RelativeSource={RelativeSource Self}}" SearchCriteriaTarget="{Binding Path=(l:ShellData.ShellData).SearchCriteria[ResultView], RelativeSource={RelativeSource Self}}">

    <ListView.ItemContainerStyle>

      <Style TargetType="{x:Type ListViewItem}">

        <Style.Triggers>

          <Trigger Property="IsMouseOver" Value="true">

            <Setter Property="Background" Value="LightBlue"/>

          </Trigger>

        </Style.Triggers>

        <Style.Resources>

          <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Blue"/>

        </Style.Resources>

      </Style>

    </ListView.ItemContainerStyle>

  </l:ShellResultView>