anchor.diff:  
   ----
   
  -Fragment Shader : 
  +Fragment Shader :
   
   [source,java]
   ----
  
positive.code: [source,java]
  ----
  
     material.setColor("Color", new ColorRGBA(1.0f, 0.0f, 0.0f, 1.0f); // red color
     material.setTexture("ColorMap", myTexture); // bind myTexture for that sampler uniform
  
  ----
  
negative.code: [source,java]
  ----
  
  #ifdef KEYMAP
    vec4 keyColor = texture2D(m_KeyMap, newTexCoord);
    diffuseColor.rgb = (1.0-keyColor.a) * diffuseColor.rgb + keyColor.a * m_KeyColor.rgb;
  #endif
  
  ----
  
  This way, a transparent pixel in the KeyMap texture doesn't modify the color. A black pixel replaces it for the m_KeyColor and values in between are blended.
  
  A result preview can be seen here:
  
  image::http://wstaw.org/m/2011/10/24/plasma-desktopuV2787.jpg[http://wstaw.org/m/2011/10/24/plasma-desktopuV2787.jpg]
  
  
  === Step by step
  