diff --git a/src/ui/android/src/org/grammaticalframework/ui/android/MainActivity.java b/src/ui/android/src/org/grammaticalframework/ui/android/MainActivity.java
index 983167df0..f448efb44 100644
--- a/src/ui/android/src/org/grammaticalframework/ui/android/MainActivity.java
+++ b/src/ui/android/src/org/grammaticalframework/ui/android/MainActivity.java
@@ -348,7 +348,7 @@ public class MainActivity extends Activity {
 				//clear the overlay
 	            mStartStopButton.getDrawable().clearColorFilter();
             } else {
-	            mStartStopButton.getDrawable().setColorFilter(0xff000000,android.graphics.PorterDuff.Mode.MULTIPLY);
+	            mStartStopButton.getDrawable().setColorFilter(0xffff0000,android.graphics.PorterDuff.Mode.SRC_ATOP);
             }
             mStartStopButton.invalidate();
         }