seqColours null

diff --git a/src/jalview/gui/AlignFrame.java b/src/jalview/gui/AlignFrame.java
index 9ea5fc5..3688462 100755 (executable)
--- a/src/jalview/gui/AlignFrame.java
+++ b/src/jalview/gui/AlignFrame.java
@@ -1477,7 +1477,7 @@ public class AlignFrame extends GAlignFrame implements DropTargetListener
   protected void deleteGroups_actionPerformed(ActionEvent e)
   {
     viewport.alignment.deleteAllGroups();
-    viewport.sequenceColours.clear();
+    viewport.sequenceColours = null;
     viewport.setSelectionGroup(null);
     PaintRefresher.Refresh(this, viewport.getSequenceSetId());
     alignPanel.repaint();