code: function ColorReplaceFilter(originalColor, newColor, epsilon) {
      PIXI.Filter.call(this,
          // vertex shader
          // vertex shader
          glslify('./colorReplace.vert'),
          // fragment shader
          glslify('./colorReplace.frag')
      );
  
      this.uniforms.originalColor = originalColor;
      this.uniforms.newColor = newColor;
      this.uniforms.epsilon = epsilon;
  }
docs: ColorReplaceFilter, originally by mishaa, updated by timetocode
  http://www.html5gamedevs.com/topic/10640-outline-a-sprite-change-certain-colors/?p=69966
  
  @class
  @param originalColor {FloatArray32} The color that will be changed, as a 3 component RGB e.g. new Float32Array(1.0, 1.0, 1.0)
  @param newColor {FloatArray32} The resulting color, as a 3 component RGB e.g. new Float32Array(1.0, 0.5, 1.0)
  @param epsilon {float} Tolerance/sensitivity of the floating-point comparison between colors (lower = more exact, higher = more inclusive)
  
  @example
  // replaces true red with true blue
  someSprite.shader = new ColorReplaceFilter(
  new Float32Array([1, 0, 0]),
  new Float32Array([0, 0, 1]),
  0.001
  );
  // replaces the RGB color 220, 220, 220 with the RGB color 225, 200, 215
  someOtherSprite.shader = new ColorReplaceFilter(
  new Float32Array([220/255.0, 220/255.0, 220/255.0]),
  new Float32Array([225/255.0, 200/255.0, 215/255.0]),
  0.001
  );