diff --git a/imagediff.js b/imagediff.js
index 279ade0..abd3088 100644
--- a/imagediff.js
+++ b/imagediff.js
@@ -194,10 +194,12 @@
       i, j, k, v;
 
     for (i = 0; i < length; i += 4) {
-      cData[i] = Math.abs(aData[i] - bData[i]);
-      cData[i+1] = Math.abs(aData[i+1] - bData[i+1]);
-      cData[i+2] = Math.abs(aData[i+2] - bData[i+2]);
-      cData[i+3] = Math.abs(255 - Math.abs(aData[i+3] - bData[i+3]));
+      var pixelA = Array.prototype.slice.call(aData, i, i+3);
+      var pixelB = Array.prototype.slice.call(bData, i, i+3);
+      var pixelC = diffPixels(pixelA, pixelB, options);
+      for (var rgbIndex = 0; rgbIndex < 4; rgbIndex++) {
+        cData[i+rgbIndex] = pixelC[rgbIndex];
+      }
     }
 
     return c;
@@ -231,7 +233,6 @@
         cData[i+0] = aData[j+0]; // r
         cData[i+1] = aData[j+1]; // g
         cData[i+2] = aData[j+2]; // b
-        // cData[i+3] = aData[j+3]; // a
       }
     }
 
@@ -241,9 +242,12 @@
       for (column = b.width; column--;) {
         i = 4 * ((row + rowOffset) * width + (column + columnOffset));
         j = 4 * (row * b.width + column);
-        cData[i+0] = Math.abs(cData[i+0] - bData[j+0]); // r
-        cData[i+1] = Math.abs(cData[i+1] - bData[j+1]); // g
-        cData[i+2] = Math.abs(cData[i+2] - bData[j+2]); // b
+        var pixelA = Array.prototype.slice.call(cData, i, i+3);
+        var pixelB = Array.prototype.slice.call(bData, j, j+3);
+        var pixelC = diffPixels(pixelA, pixelB, options);
+        for (var rgbIndex = 0; rgbIndex < 4; rgbIndex++) {
+          cData[i+rgbIndex] = pixelC[rgbIndex];
+        }
       }
     }
 
@@ -261,6 +265,35 @@
     return c;
   }
 
+  /**
+   * Differentiates two rgb pixels by subtracting color values.
+   * @see https://github.com/HumbleSoftware/js-imagediff/pull/52
+   *
+   * @param {Object} options
+   *   options.lightboost: increases differences visibility with a light boost.
+   *   options.diffColor: a rgb array used to specify differences color instead of light gap.
+   *   options.stack: stacks differences on top of the original image, preserving common pixels.
+   *
+   * @returns {Array} pixel rgba values between 0 and 255.
+   */
+  function diffPixels(pixelA, pixelB, options) {
+    var lightboost = options && options.lightboost || 0;
+    var diffColor = options && options.diffColor || false;
+    var stack = options && options.stack || false;
+    // pixel = [r,g,b,a]
+    var pixelC = [0,0,0,255];
+    for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
+      pixelC[rgbIndex] = Math.abs(pixelA[rgbIndex] - pixelB[rgbIndex]);
+      if (pixelC[rgbIndex] > 0) {
+        if (diffColor) pixelC[rgbIndex] = diffColor[rgbIndex];
+        pixelC[rgbIndex] = Math.min(pixelC[rgbIndex] + lightboost, 255);
+      }
+      else if (stack) {
+        pixelC[rgbIndex] = pixelA[rgbIndex];
+      }
+    }
+    return pixelC;
+  }
 
   // Validation
   function checkType () {
diff --git a/js/imagediff.js b/js/imagediff.js
index 275d6f8..9b5dbcd 100644
--- a/js/imagediff.js
+++ b/js/imagediff.js
@@ -187,10 +187,12 @@
       i, j, k, v;
 
     for (i = 0; i < length; i += 4) {
-      cData[i] = Math.abs(aData[i] - bData[i]);
-      cData[i+1] = Math.abs(aData[i+1] - bData[i+1]);
-      cData[i+2] = Math.abs(aData[i+2] - bData[i+2]);
-      cData[i+3] = Math.abs(255 - Math.abs(aData[i+3] - bData[i+3]));
+      var pixelA = Array.prototype.slice.call(aData, i, i+3);
+      var pixelB = Array.prototype.slice.call(bData, i, i+3);
+      var pixelC = diffPixels(pixelA, pixelB, options);
+      for (var rgbIndex = 0; rgbIndex < 4; rgbIndex++) {
+        cData[i+rgbIndex] = pixelC[rgbIndex];
+      }
     }
 
     return c;
@@ -224,7 +226,6 @@
         cData[i+0] = aData[j+0]; // r
         cData[i+1] = aData[j+1]; // g
         cData[i+2] = aData[j+2]; // b
-        // cData[i+3] = aData[j+3]; // a
       }
     }
 
@@ -234,9 +235,12 @@
       for (column = b.width; column--;) {
         i = 4 * ((row + rowOffset) * width + (column + columnOffset));
         j = 4 * (row * b.width + column);
-        cData[i+0] = Math.abs(cData[i+0] - bData[j+0]); // r
-        cData[i+1] = Math.abs(cData[i+1] - bData[j+1]); // g
-        cData[i+2] = Math.abs(cData[i+2] - bData[j+2]); // b
+        var pixelA = Array.prototype.slice.call(cData, i, i+3);
+        var pixelB = Array.prototype.slice.call(bData, j, j+3);
+        var pixelC = diffPixels(pixelA, pixelB, options);
+        for (var rgbIndex = 0; rgbIndex < 4; rgbIndex++) {
+          cData[i+rgbIndex] = pixelC[rgbIndex];
+        }
       }
     }
 
@@ -254,6 +258,35 @@
     return c;
   }
 
+  /**
+   * Differentiates two rgb pixels by subtracting color values.
+   * @see https://github.com/HumbleSoftware/js-imagediff/pull/52
+   *
+   * @param {Object} options
+   *   options.lightboost: increases differences visibility with a light boost.
+   *   options.diffColor: a rgb array used to specify differences color instead of light gap.
+   *   options.stack: stacks differences on top of the original image, preserving common pixels.
+   *
+   * @returns {Array} pixel rgba values between 0 and 255.
+   */
+  function diffPixels(pixelA, pixelB, options) {
+    var lightboost = options && options.lightboost || 0;
+    var diffColor = options && options.diffColor || false;
+    var stack = options && options.stack || false;
+    // pixel = [r,g,b,a]
+    var pixelC = [0,0,0,255];
+    for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
+      pixelC[rgbIndex] = Math.abs(pixelA[rgbIndex] - pixelB[rgbIndex]);
+      if (pixelC[rgbIndex] > 0) {
+        if (diffColor) pixelC[rgbIndex] = diffColor[rgbIndex];
+        pixelC[rgbIndex] = Math.min(pixelC[rgbIndex] + lightboost, 255);
+      }
+      else if (stack) {
+        pixelC[rgbIndex] = pixelA[rgbIndex];
+      }
+    }
+    return pixelC;
+  }
 
   // Validation
   function checkType () {
diff --git a/spec/ImageDiffSpec.js b/spec/ImageDiffSpec.js
index 67299b4..ad8b88a 100644
--- a/spec/ImageDiffSpec.js
+++ b/spec/ImageDiffSpec.js
@@ -312,14 +312,29 @@ describe('ImageUtils', function() {
       });
 
       it('should calculate difference', function () {
+        a = imagediff.createImageData(1, 1),
+        a.data[1] = 200,
+        b = imagediff.createImageData(1, 1),
+        b.data[1] = 158,
+        c = imagediff.diff(a, b),
+
+        d = imagediff.createImageData(1, 1);
+        d.data[1] = 42;
+        d.data[3] = 255;
+
+        expect(c).toImageDiffEqual(d);
+      });
+
+      it('should calculate color difference with adjusted lightness', function () {
         a = imagediff.createImageData(1, 1),
         a.data[1] = 200;
         b = imagediff.createImageData(1, 1),
         b.data[1] = 158;
-        c = imagediff.diff(a, b);
+        c = imagediff.diff(a, b, {lightboost: 155});
 
         d = imagediff.createImageData(1, 1);
-        d.data[1] = 42;
+        // a-b + 155
+        d.data[1] = 197;
         d.data[3] = 255;
 
         expect(c).toImageDiffEqual(d);
@@ -361,6 +376,36 @@ describe('ImageUtils', function() {
 
         expect(c).toImageDiffEqual(d);
       });
+
+      it('should optionally color differences', function () {
+        a = imagediff.createImageData(1, 1),
+        b = imagediff.createImageData(1, 1);
+        // Fills a grey pixel and expects c to be tinted in light pink
+        Array.prototype.forEach.call(b.data, function (value, i) {
+          b.data[i] = 125;
+        });
+        c = imagediff.diff(a, b, {diffColor: [255,0,44], lightboost: 191});
+
+        d = imagediff.createImageData(1, 1);
+        d.data[0] = 255;
+        d.data[1] = 191;
+        d.data[2] = 235;
+        d.data[3] = 255;
+
+        expect(c).toImageDiffEqual(d);
+      });
+
+      it('should optionally show common pixels', function () {
+        a = imagediff.createImageData(1, 1);
+        // Fills white pixels
+        Array.prototype.forEach.call(a.data, function (value, i) {
+          a.data[i] = 255;
+        });
+        b = a;
+        c = imagediff.diff(a, b, {stack: true});
+
+        expect(c).toImageDiffEqual(a);
+      });
     });
 
     /*