diff --git a/HISTORY.md b/HISTORY.md
index 69dee39a..1b174c9c 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -8,6 +8,10 @@
 * **Notable Fixes:**
     * work around a floating point precision glitch in "ray length"
     * fixed an occasional rendering glitch when changing the display style of a variable watcher
+    * fixed color effect for negative inputs, thanks, Brian!
+
+### 2021-04-23
+* objects: fixed color effect for negative inputs, thanks, Brian!
 
 ### 2021-04-17
 * objects: fixed an occasional rendering glitch when changing the display style of a variable watcher
diff --git a/snap.html b/snap.html
index d1998ca9..3d402453 100755
--- a/snap.html
+++ b/snap.html
@@ -10,7 +10,7 @@
         <script src="src/widgets.js?version=2021-01-05"></script>
         <script src="src/blocks.js?version=2021-02-27"></script>
         <script src="src/threads.js?version=2021-04-17"></script>
-        <script src="src/objects.js?version=2021-04-20"></script>
+        <script src="src/objects.js?version=2021-04-23"></script>
         <script src="src/gui.js?version=2021-04-17"></script>
         <script src="src/paint.js?version=2020-05-17"></script>
         <script src="src/lists.js?version=2021-03-15"></script>
diff --git a/src/objects.js b/src/objects.js
index bb1b6678..9a042105 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -84,7 +84,7 @@ BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph,  BooleanSlotMorph,
 localize, TableMorph, TableFrameMorph, normalizeCanvas, VectorPaintEditorMorph,
 AlignmentMorph, Process, WorldMap, copyCanvas, useBlurredShadows*/
 
-modules.objects = '2021-April-20';
+modules.objects = '2021-April-23';
 
 var SpriteMorph;
 var StageMorph;
@@ -5113,7 +5113,7 @@ SpriteMorph.prototype.applyGraphicsEffects = function (canvas) {
             }
             v = max / 255;
 
-            h = (((h + hueShift * 360 / 200) % 360)+360)%360;
+            h = (((h + hueShift * 360 / 200) % 360) + 360) % 360;
             s = Math.max(0, Math.min(s + saturationShift / 100, 1));
             v = Math.max(0, Math.min(v + brightnessShift / 100, 1));