-    wxColour fg = wxColour ( (unsigned char)(MostFreqCol >> 16),
-                             (unsigned char)(MostFreqCol >> 8),
-                             (unsigned char)(MostFreqCol) );
+    wxColour fg = wxColour ( (unsigned char)(colMostFreq >> 16),
+                             (unsigned char)(colMostFreq >> 8),
+                             (unsigned char)(colMostFreq) );
+
+    wxColour bg = wxColour ( (unsigned char)(colNextMostFreq >> 16),
+                             (unsigned char)(colNextMostFreq >> 8),
+                             (unsigned char)(colNextMostFreq) );
+
+    int fg_intensity = fg.Red() + fg.Green() + fg.Blue();
+    int bg_intensity = bg.Red() + bg.Green() + bg.Blue();
+
+    if (bg_intensity > fg_intensity)
+    {
+        //swap fg and bg
+        wxColour tmp = fg;
+        fg = bg;
+        bg = tmp;
+    }