Here's the line you're looking for:
<Page AbsorbsInput="false" BackgroundColor="#FF0000" BackgroundOpacity="1.000" GetsInput="false" Location="14,171" Name="ResultColorPage" ScrollExtent="18,18" Size="18,18" Visible="false"/>
Anyhow, it's the one with Name="ResultColorPage" in it. Mine's from the fetish tradeskill page, so exact line might be different.
You can change the location to "-200,-200" or something and that will get it out of view.
The game forces visibility and opacity, so you cannot hide with those.
One other thing you could try is simply move that line after the event icon line in the xml. That should make the green/red show up but be completely covered by the event icon.
Just a few quick thoughts. If none of those work, write back and I'll think some more. It is definitely doable.