Index: src/sas/qtgui/Calculators/DataOperationUtilityPanel.py
===================================================================
--- src/sas/qtgui/Calculators/DataOperationUtilityPanel.py	(revision cee5c78929349ae10afc88cb8b95e0c907f1826a)
+++ src/sas/qtgui/Calculators/DataOperationUtilityPanel.py	(revision 7fb471d81b5d11daed3df86a4e8427e6a832cf7a)
@@ -273,5 +273,5 @@
                 msg = 'DataOperation: Number requires a float number'
                 logging.warning(msg)
-                self.txtNumber.setStyleSheet(QtCore.QString(BG_RED))
+                self.txtNumber.setStyleSheet(BG_RED)
 
             elif float(self.txtNumber.text()) == 0.:
@@ -279,8 +279,8 @@
                 msg = 'DataOperation: Number requires a non zero number'
                 logging.warning(msg)
-                self.txtNumber.setStyleSheet(QtCore.QString(BG_RED))
+                self.txtNumber.setStyleSheet(BG_RED)
 
             else:
-                self.txtNumber.setStyleSheet(QtCore.QString(BG_WHITE))
+                self.txtNumber.setStyleSheet(BG_WHITE)
                 self.data2 = float(self.txtNumber.text())
                 self.updatePlot(self.graphData2, self.layoutData2, self.data2)
@@ -293,11 +293,11 @@
         else:
             if self.cbData2.currentText() == 'Number':
-                self.cbData1.setStyleSheet(QtCore.QString(BG_WHITE))
-                self.cbData2.setStyleSheet(QtCore.QString(BG_WHITE))
+                self.cbData1.setStyleSheet(BG_WHITE)
+                self.cbData2.setStyleSheet(BG_WHITE)
                 return True
 
             elif self.data1.__class__.__name__ != self.data2.__class__.__name__:
-                self.cbData1.setStyleSheet(QtCore.QString(BG_RED))
-                self.cbData2.setStyleSheet(QtCore.QString(BG_RED))
+                self.cbData1.setStyleSheet(BG_RED)
+                self.cbData2.setStyleSheet(BG_RED)
                 print(self.data1.__class__.__name__ != self.data2.__class__.__name__)
                 logging.warning('Cannot compute data of different dimensions')
@@ -308,6 +308,6 @@
                              not all(i == j for i, j in zip(self.data1.x, self.data2.x))):
                 logging.warning('Cannot compute 1D data of different lengths')
-                self.cbData1.setStyleSheet(QtCore.QString(BG_RED))
-                self.cbData2.setStyleSheet(QtCore.QString(BG_RED))
+                self.cbData1.setStyleSheet(BG_RED)
+                self.cbData2.setStyleSheet(BG_RED)
                 return False
 
@@ -320,12 +320,12 @@
                                 zip(self.data1.qy_data, self.data2.qy_data))
                          ):
-                self.cbData1.setStyleSheet(QtCore.QString(BG_RED))
-                self.cbData2.setStyleSheet(QtCore.QString(BG_RED))
+                self.cbData1.setStyleSheet(BG_RED)
+                self.cbData2.setStyleSheet(BG_RED)
                 logging.warning('Cannot compute 2D data of different lengths')
                 return False
 
             else:
-                self.cbData1.setStyleSheet(QtCore.QString(BG_WHITE))
-                self.cbData2.setStyleSheet(QtCore.QString(BG_WHITE))
+                self.cbData1.setStyleSheet(BG_WHITE)
+                self.cbData2.setStyleSheet(BG_WHITE)
                 return True
 
@@ -333,18 +333,18 @@
         """ Check that name of output does not already exist """
         name_to_check = str(self.txtOutputData.text())
-        self.txtOutputData.setStyleSheet(QtCore.QString(BG_WHITE))
+        self.txtOutputData.setStyleSheet(BG_WHITE)
 
         if name_to_check is None or name_to_check == '':
-            self.txtOutputData.setStyleSheet(QtCore.QString(BG_RED))
+            self.txtOutputData.setStyleSheet(BG_RED)
             logging.warning('No output name')
             return False
 
         elif name_to_check in self.list_data_items:
-            self.txtOutputData.setStyleSheet(QtCore.QString(BG_RED))
+            self.txtOutputData.setStyleSheet(BG_RED)
             logging.warning('The Output data name already exists')
             return False
 
         else:
-            self.txtOutputData.setStyleSheet(QtCore.QString(BG_WHITE))
+            self.txtOutputData.setStyleSheet(BG_WHITE)
             return True
 
