ScrollBar in Frame control

Look, I wrote such code:
    <Grid>
    <Frame Content="Frame" Margin="28,13,39,22" Name="frame1" Source="http://google.com">
      <Frame.Resources>
        <Style TargetType="ScrollBar">
          <Setter Property="Background" Value="#FFFFFF00"/>
        </Style>
      </Frame.Resources>
    </Frame>
    </Grid>


But the background color of the scrollbars didn't change Maybe I misunderstood You?