diff --git a/resources/shaders/tv.frag b/resources/shaders/tv.frag
index f6c3ccc..79b35fb 100644
--- a/resources/shaders/tv.frag
+++ b/resources/shaders/tv.frag
@@ -13,7 +13,7 @@
 
 // The content from common.glsl is automatically prepended to each shader effect.
 
-uniform vec3 uColor;
+uniform vec4 uColor;
 
 const float BLUR_WIDTH = 0.01;  // Width of the gradients.
 const float TB_TIME    = 0.7;   // Relative time for the top/bottom animation.
@@ -61,7 +61,7 @@ void main() {
     oColor.rgb /= oColor.a;
   }
 
-  oColor.rgb = mix(oColor.rgb, uColor * oColor.a, smoothstep(0.0, 1.0, prog));
+  oColor.rgb = mix(oColor.rgb, uColor.rgb * oColor.a, smoothstep(0.0, 1.0, prog));
   oColor.a *= mask;
 
   // These are pretty useful for understanding how this works.
diff --git a/src/TVEffect.js b/src/TVEffect.js
index f1cfe5f..b02d8bd 100644
--- a/src/TVEffect.js
+++ b/src/TVEffect.js
@@ -50,8 +50,8 @@ var TVEffect = class {
       // Write all uniform values at the start of each animation.
       shader.connect('begin-animation', (shader, settings) => {
         const c = Clutter.Color.from_string(settings.get_string('tv-effect-color'))[1];
-        shader.set_uniform_float(shader._uColor, 3,
-                                 [c.red / 255, c.green / 255, c.blue / 255]);
+        shader.set_uniform_float(shader._uColor, 4,
+                                 [c.red / 255, c.green / 255, c.blue / 255, 1.0]);
       });
     });
   }