Access current theme background color of Ribbon

I want to be able to define styles for the TabControl, DocumentWindow, etc. used in my app so that the background color matches the background color of the Ribbon control for the current theme of the app.  In addition, I have some triggers that set the background of my edit controls when the control is readonly:

<Style TargetType="editors:TextBox">
    <Style.Triggers>
        <Trigger Property="IsReadOnly" Value="true">
            <Setter Property="Control.Background" >
                <Setter.Value>
                    <SolidColorBrush Color="#FFF9F9F9"/>
                </Setter.Value>
           </Setter> 
           <Setter Property="Control.FontWeight" Value="SemiBold" />
        </Trigger>
    </Style.Triggers>
</Style>

As you can see above, I have the brush color hardcoded but I want to be able to have it match whatever the background color of the ribbon control that my app is using.

Is this possible?

- Brad