[TD]add light text on dark page mode

- some visually impaired users need white graphics on
  dark page.

- revise Annotation dialog to respect dark style

src/Mod/TechDraw/Gui/QGIFace.cpp

@@ -38,6 +38,7 @@
 #include <Base/Parameter.h>
 #include <Mod/TechDraw/App/DrawUtil.h>
 
+#include "PreferencesGui.h"
 #include "QGIFace.h"
 #include <QByteArrayMatcher>
 #include "QGCustomImage.h"
@@ -48,7 +49,6 @@
 #include "Rez.h"
 #include "ZVALUE.h"
 
-
 using namespace TechDrawGui;
 using namespace TechDraw;
 
@@ -64,7 +64,7 @@ QGIFace::QGIFace(int index) :
 
     //setStyle(Qt::NoPen);    //don't draw face lines, just fill for debugging
     setStyle(Qt::DashLine);
-    m_geomColor = QColor(Qt::black);
+    m_geomColor = PreferencesGui::getAccessibleQColor(QColor(Qt::black));
     setLineWeight(0.5);                   //0 = cosmetic
 
     setPrettyNormal();