rounded corners for colorscale popover

common/gtk-3.0/3.20/gtk-dark.css

@@ -2595,6 +2595,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #404552; }
   .content-view:hover {

common/gtk-3.0/3.20/gtk-darker.css

@@ -2594,6 +2594,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #ffffff; }
   .content-view:hover {

common/gtk-3.0/3.20/gtk-solid-dark.css

@@ -2595,6 +2595,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #404552; }
   .content-view:hover {

common/gtk-3.0/3.20/gtk-solid-darker.css

@@ -2594,6 +2594,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #ffffff; }
   .content-view:hover {

common/gtk-3.0/3.20/gtk-solid.css

@@ -2598,6 +2598,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #ffffff; }
   .content-view:hover {

common/gtk-3.0/3.20/gtk.css

@@ -2598,6 +2598,9 @@ button.color {
     margin: 4px;
     border-radius: 0; }
 
+colorchooser .popover.osd {
+  border-radius: 3px; }
+
 .content-view {
   background-color: #ffffff; }
   .content-view:hover {

common/gtk-3.0/3.20/sass/_common.scss

@@ -2809,6 +2809,9 @@ button.color {
   }
 }
 
+// colorscale popup
+colorchooser .popover.osd { border-radius: 3px; }
+
 //
 // Misc
 //