diff --git a/libs/core.js b/libs/core.js
index 00c5430f..6c6cfc0d 100644
--- a/libs/core.js
+++ b/libs/core.js
@@ -445,7 +445,9 @@ core.prototype.keyDown = function(keyCode) {
                     core.status.usingCenterFly = false;
                 } else {
                     core.status.usingCenterFly = true;
-                    core.fillRect('ui',(12-core.getHeroLoc('x'))*32,(12-core.getHeroLoc('y'))*32,32,32,'rgba(0,255,0,0.5)');
+                    var fillstyle = 'rgba(255,0,0,0.5)';
+                    if (core.canUseItem('centerFly')) fillstyle = 'rgba(0,255,0,0.5)';
+                    core.fillRect('ui',(12-core.getHeroLoc('x'))*32,(12-core.getHeroLoc('y'))*32,32,32,fillstyle);
                 }
             }
             break;
diff --git a/libs/events.js b/libs/events.js
index f8af663c..74f6a00e 100644
--- a/libs/events.js
+++ b/libs/events.js
@@ -459,7 +459,9 @@ events.prototype.useItem = function(itemId) {
     }
     if (itemId=='centerFly') {
         core.status.usingCenterFly= true;
-        core.fillRect('ui',(12-core.getHeroLoc('x'))*32,(12-core.getHeroLoc('y'))*32,32,32,'rgba(0,255,0,0.5)');
+        var fillstyle = 'rgba(255,0,0,0.5)';
+        if (core.canUseItem('centerFly')) fillstyle = 'rgba(0,255,0,0.5)';
+        core.fillRect('ui',(12-core.getHeroLoc('x'))*32,(12-core.getHeroLoc('y'))*32,32,32,fillstyle);
         return;
     }