--- gigedit/trunk/src/gigedit/dimregionedit.cpp	2019/10/01 16:27:13	3621
+++ gigedit/trunk/src/gigedit/dimregionedit.cpp	2019/10/01 16:41:06	3622
@@ -186,6 +186,14 @@
         auto setOrangeColor = [&] {
             cr->set_source_rgba(255.f, 177/255.f, 82/255.f, sensitive ? 1.0 : 0.3);
         };
+        auto setWhiteColor = [&] {
+            cr->set_source_rgba(255.f, 255.f, 255.f, sensitive ? 1.0 : 0.3);
+        };
+
+        // fill background white
+        cr->rectangle(0, 0, w, h);
+        setWhiteColor();
+        cr->fill();
 
         // draw horizontal center line (dashed gray) if LFO range is signed
         if (signedRange) {