diff --git a/vncviewer/OptionsDialog.cxx b/vncviewer/OptionsDialog.cxx
index 93e7f0c..cfed1fc 100644
--- a/vncviewer/OptionsDialog.cxx
+++ b/vncviewer/OptionsDialog.cxx
@@ -121,6 +121,10 @@
       enableItem(IDC_ENCODING_ZRLE, ok);
       enableItem(IDC_ENCODING_HEXTILE, ok);
       enableItem(IDC_ENCODING_RAW, ok);
+      enableItem(IDC_FORMAT_FULLCOLOUR, ok);
+      enableItem(IDC_FORMAT_MEDIUMCOLOUR, ok);
+      enableItem(IDC_FORMAT_LOWCOLOUR, ok);
+      enableItem(IDC_FORMAT_VERYLOWCOLOUR, ok);
       return true;
     }
     return false;
diff --git a/vncviewer_unix/OptionsDialog.h b/vncviewer_unix/OptionsDialog.h
index 3963990..9c52437 100644
--- a/vncviewer_unix/OptionsDialog.h
+++ b/vncviewer_unix/OptionsDialog.h
@@ -120,6 +120,10 @@
     zrle.disabled(autoSelect.checked());
     hextile.disabled(autoSelect.checked());
     raw.disabled(autoSelect.checked());
+    fullColour.disabled(autoSelect.checked());
+    mediumColour.disabled(autoSelect.checked());
+    lowColour.disabled(autoSelect.checked());
+    veryLowColour.disabled(autoSelect.checked());
     sendPrimary.disabled(!sendClipboard.checked());
     dotWhenNoCursor.disabled(!useLocalCursor.checked());
   }
@@ -143,6 +147,10 @@
       zrle.disabled(autoSelect.checked());
       hextile.disabled(autoSelect.checked());
       raw.disabled(autoSelect.checked());
+      fullColour.disabled(autoSelect.checked());
+      mediumColour.disabled(autoSelect.checked());
+      lowColour.disabled(autoSelect.checked());
+      veryLowColour.disabled(autoSelect.checked());
     } else if (checkbox == &fullColour || checkbox == &mediumColour ||
                checkbox == &lowColour || checkbox == &veryLowColour) {
       fullColour.checked(checkbox == &fullColour);