It's the tags <textcolor> and <disabledcolor> you are looking for
<control>
<description>fade background</description>
<type>image</type>
<id>1</id>
<posX>0</posX>
<posY>464</posY>
<width>525</width>
<height>304</height>
<texture>overlay_fadebg.png</texture>
<visible>player.hasmedia + [!window.isvisible(7987) + !window.isvisible(96742) + !Control.IsVisible(51) | Control.IsVisible(50)]</visible>
</control>