diff --git a/src/engine/Debug/DebugFlags.ts b/src/engine/Debug/DebugFlags.ts
index 7ca4a4d7..c2574da2 100644
--- a/src/engine/Debug/DebugFlags.ts
+++ b/src/engine/Debug/DebugFlags.ts
@@ -9,20 +9,43 @@ export interface DebugFlags {
 
 export class ColorBlindFlags {
   private _engine: Engine;
+  private _colorBlindPostProcessor: ColorBlindnessPostProcessor;
 
   constructor(engine: Engine) {
     this._engine = engine;
+    this._colorBlindPostProcessor = new ColorBlindnessPostProcessor(ColorBlindnessMode.Protanope);
   }
 
+  /**
+   * Correct colors for a specified color blindness
+   * @param colorBlindness
+   */
   public correct(colorBlindness: ColorBlindnessMode) {
     if (this._engine.graphicsContext instanceof ExcaliburGraphicsContextWebGL) {
-      this._engine.graphicsContext.addPostProcessor(new ColorBlindnessPostProcessor(colorBlindness, false));
+      this.clear();
+      this._colorBlindPostProcessor.colorBlindnessMode = colorBlindness;
+      this._colorBlindPostProcessor.simulate = false;
+      this._engine.graphicsContext.addPostProcessor(this._colorBlindPostProcessor);
     }
   }
 
+  /**
+   * Simulate colors for a specified color blindness
+   * @param colorBlindness
+   */
   public simulate(colorBlindness: ColorBlindnessMode) {
     if (this._engine.graphicsContext instanceof ExcaliburGraphicsContextWebGL) {
-      this._engine.graphicsContext.addPostProcessor(new ColorBlindnessPostProcessor(colorBlindness, true));
+      this.clear();
+      this._colorBlindPostProcessor.colorBlindnessMode = colorBlindness;
+      this._colorBlindPostProcessor.simulate = true;
+      this._engine.graphicsContext.addPostProcessor(this._colorBlindPostProcessor);
     }
   }
+
+  /**
+   * Remove color blindness post processor
+   */
+  public clear() {
+    this._engine.graphicsContext.removePostProcessor(this._colorBlindPostProcessor);
+  }
 }
diff --git a/src/engine/Graphics/PostProcessor/ColorBlindnessPostProcessor.ts b/src/engine/Graphics/PostProcessor/ColorBlindnessPostProcessor.ts
index 4865d344..b7829df4 100644
--- a/src/engine/Graphics/PostProcessor/ColorBlindnessPostProcessor.ts
+++ b/src/engine/Graphics/PostProcessor/ColorBlindnessPostProcessor.ts
@@ -27,16 +27,18 @@ export class ColorBlindnessPostProcessor implements PostProcessor {
   }
 
   set colorBlindnessMode(colorBlindMode: ColorBlindnessMode) {
-    const shader = this._shader.getShader();
-    shader.use();
-    if (this._colorBlindnessMode === ColorBlindnessMode.Protanope) {
-      shader.setUniformInt('u_type', 0);
-    } else if (this._colorBlindnessMode === ColorBlindnessMode.Deuteranope) {
-      shader.setUniformInt('u_type', 1);
-    } else if (this._colorBlindnessMode === ColorBlindnessMode.Tritanope) {
-      shader.setUniformInt('u_type', 2);
-    }
     this._colorBlindnessMode = colorBlindMode;
+    if (this._shader) {
+      const shader = this._shader.getShader();
+      shader.use();
+      if (this._colorBlindnessMode === ColorBlindnessMode.Protanope) {
+        shader.setUniformInt('u_type', 0);
+      } else if (this._colorBlindnessMode === ColorBlindnessMode.Deuteranope) {
+        shader.setUniformInt('u_type', 1);
+      } else if (this._colorBlindnessMode === ColorBlindnessMode.Tritanope) {
+        shader.setUniformInt('u_type', 2);
+      }
+    }
   }
 
   get colorBlindnessMode(): ColorBlindnessMode {
@@ -44,10 +46,13 @@ export class ColorBlindnessPostProcessor implements PostProcessor {
   }
 
   set simulate(value: boolean) {
-    const shader = this._shader.getShader();
-    shader.use();
     this._simulate = value;
-    shader.setUniformBoolean('u_simulate', value);
+    if (this._shader) {
+
+      const shader = this._shader.getShader();
+      shader.use();
+      shader.setUniformBoolean('u_simulate', value);
+    }
   }
 
   get simulate(): boolean {