demo.xml

<synth>
    <style id="backingStyle">
        <opaque value="TRUE"/>
        <font name="Dialog" size="12"/>
        <state>
            <color value="WHITE" type="BACKGROUND"/>
            <color value="BLACK" type="FOREGROUND"/>
        </state>
    </style>
    <bind style="backingStyle" type="region" key=".*"/>

    <style id="SliderTrackStyle">
        <opaque value="TRUE"/>
        <state>
            <color type="BACKGROUND" value="ORANGE"/>
        </state>
    </style>
    <bind style="SliderTrackStyle" type="region" key="SliderTrack" />

    <style id="SliderThumbStyle">
        <opaque value="TRUE"/>
        <state>
            <color type="BACKGROUND" value="RED"/>
        </state>
        <state value="PRESSED">
            <color type="BACKGROUND" value="BLACK"/>
        </state>    
    </style>
    <bind style="SliderThumbStyle" type="region" key="SliderThumb" />
</synth>