Adjusted dark.qss to avoid QMdiSubWindow issues.

Removed implicit styling of QMdiSubWindow from dark theme.


Readjusted text color in QwtPlots.

ApplicationCode/Resources/themes/dark.qss

@@ -75,6 +75,10 @@ RiuQwtPlotWidget {
     color: $textColor;
 }
 
+QwtPlot QWidget {
+   color: $textColor;
+}
+
 QwtTextLabel {
     color: $textColor;
 }
@@ -150,7 +154,7 @@ QLabel {
     background-color: transparent;
 }
 
-QWidget {
+.QWidget, QFrame, QMainWindow, QDialog, QMenu, QLabel, QCheckBox, QTabBar, QDockWidget {
     background-color: $mainBackgroundColor;
     color: $textColor;
     border-color: $borderColor;