diff --git a/3-mid/opengl/assets/shader/colored_textured.frag b/3-mid/opengl/assets/shader/colored_textured.frag
index df48ccd..1eb7343 100644
--- a/3-mid/opengl/assets/shader/colored_textured.frag
+++ b/3-mid/opengl/assets/shader/colored_textured.frag
@@ -1,15 +1,24 @@
-#version 140
+// Include 'version.header'.
+// Include 'texturing-frag.snippet'.
 
-uniform sampler2D   sTexture; 
+in  vec3       frag_Site;
+in  vec4       frag_Color;
+in  vec2       frag_Coords;
 
-varying vec4        vColor;
-varying vec2        vCoords;
+out vec4       final_Color;
 
 
-void main()
+void
+main()
 {
-   gl_FragColor =   mix (texture2D (sTexture, vCoords),
-                         vColor,
-                         0.5);
-}
+    vec4   surface_Color = mix (apply_Texturing (frag_Coords),
+                                frag_Color,
+                                0.5);
 
+    vec3  Gamma = vec3 (1.0 / 2.2);
+    final_Color = vec4 
+    (pow
+     (surface_Color.rgb,     // Final color (after gamma correction).
+                             Gamma),
+                        surface_Color.a);
+}
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/colored_textured.vert b/3-mid/opengl/assets/shader/colored_textured.vert
index 6e5af10..e92e31e 100644
--- a/3-mid/opengl/assets/shader/colored_textured.vert
+++ b/3-mid/opengl/assets/shader/colored_textured.vert
@@ -3,17 +3,17 @@
 uniform   mat4   mvp_Transform;
 uniform   vec3   Scale;
 
-attribute vec3   Site;
-attribute vec4   Color;
-attribute vec2   Coords;
+in  vec3   Site;
+in  vec4   Color;
+in  vec2   Coords;
 
-varying   vec4   vColor;
-varying   vec2   vCoords;
+out vec4   frag_Color;
+out vec2   frag_Coords;
 
 
 void main()
 {
    gl_Position = mvp_Transform * vec4 (Site * Scale, 1.0);
-   vColor      = Color;
-   vCoords     = Coords;
+   frag_Color  = Color;
+   frag_Coords = Coords;
 }
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-colored_textured.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-colored_textured.adb
index 32c5f2d..eca5e4a 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-colored_textured.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-colored_textured.adb
@@ -78,7 +78,9 @@ is
             white_Texture := openGL.Texture.Forge.to_Texture (white_Image);
 
             vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/colored_textured.vert");
-            fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/colored_textured.frag");
+            fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                                    2 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+                                                                    3 => to_Asset ("assets/opengl/shader/colored_textured.frag"))));
 
             the_Program := new openGL.Program.item;
             the_Program.define (vertex_Shader  'Access,