diff --git a/lib/optimizer/level-1/optimize.js b/lib/optimizer/level-1/optimize.js
index 13cfd8c52..67ef4a197 100644
--- a/lib/optimizer/level-1/optimize.js
+++ b/lib/optimizer/level-1/optimize.js
@@ -89,16 +89,25 @@ function optimizeBorderRadius(property) {
   }
 }
 
+/**
+ * @param {string} name
+ * @param {string} value
+ * @param {Object} compatibility
+ * @return {string}
+ */
 function optimizeColors(name, value, compatibility) {
-  if (value.indexOf('#') === -1 && value.indexOf('rgb') == -1 && value.indexOf('hsl') == -1) {
+  if (!value.match(/#|rgb|hsl/gi)) {
     return shortenHex(value);
   }
 
   value = value
-    .replace(/rgb\((\-?\d+),(\-?\d+),(\-?\d+)\)/g, function (match, red, green, blue) {
+    .replace(/(rgb|hsl)a?\((\-?\d+),(\-?\d+\%?),(\-?\d+\%?),(0*[1-9]+[0-9]*(.?\d*)?)\)/gi, function (match, colorFn, p1, p2, p3, alpha) {
+      return (parseInt(alpha, 10) >= 1 ? colorFn + '(' + [p1,p2,p3].join(',') + ')' : match);
+    })
+    .replace(/rgb\((\-?\d+),(\-?\d+),(\-?\d+)\)/gi, function (match, red, green, blue) {
       return shortenRgb(red, green, blue);
     })
-    .replace(/hsl\((-?\d+),(-?\d+)%?,(-?\d+)%?\)/g, function (match, hue, saturation, lightness) {
+    .replace(/hsl\((-?\d+),(-?\d+)%?,(-?\d+)%?\)/gi, function (match, hue, saturation, lightness) {
       return shortenHsl(hue, saturation, lightness);
     })
     .replace(/(^|[^='"])#([0-9a-f]{6})/gi, function (match, prefix, color, at, inputValue) {
@@ -115,12 +124,13 @@ function optimizeColors(name, value, compatibility) {
     .replace(/(^|[^='"])#([0-9a-f]{3})/gi, function (match, prefix, color) {
       return prefix + '#' + color.toLowerCase();
     })
-    .replace(/(rgb|rgba|hsl|hsla)\(([^\)]+)\)/g, function (match, colorFunction, colorDef) {
+    .replace(/(rgb|rgba|hsl|hsla)\(([^\)]+)\)/gi, function (match, colorFunction, colorDef) {
       var tokens = colorDef.split(',');
-      var applies = (colorFunction == 'hsl' && tokens.length == 3) ||
-        (colorFunction == 'hsla' && tokens.length == 4) ||
-        (colorFunction == 'rgb' && tokens.length == 3 && colorDef.indexOf('%') > 0) ||
-        (colorFunction == 'rgba' && tokens.length == 4 && colorDef.indexOf('%') > 0);
+      var colorFnLowercase = colorFunction && colorFunction.toLowerCase();
+      var applies = (colorFnLowercase == 'hsl' && tokens.length == 3) ||
+        (colorFnLowercase == 'hsla' && tokens.length == 4) ||
+        (colorFnLowercase == 'rgb' && tokens.length === 3 && colorDef.indexOf('%') > 0) ||
+        (colorFnLowercase == 'rgba' && tokens.length == 4 && colorDef.indexOf('%') > 0);
 
       if (!applies) {
         return match;
diff --git a/lib/optimizer/validator.js b/lib/optimizer/validator.js
index fd3fb97e4..7140bed7f 100644
--- a/lib/optimizer/validator.js
+++ b/lib/optimizer/validator.js
@@ -6,11 +6,11 @@ var functionAnyRegexStr = '(' + variableRegexStr + '|' + functionNoVendorRegexSt
 var calcRegex = new RegExp('^(\\-moz\\-|\\-webkit\\-)?calc\\([^\\)]+\\)$', 'i');
 var decimalRegex = /[0-9]/;
 var functionAnyRegex = new RegExp('^' + functionAnyRegexStr + '$', 'i');
-var hslColorRegex = /^hsl\(\s{0,31}[\-\.]?\d+\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+%\s{0,31}\)|hsla\(\s{0,31}[\-\.]?\d+\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+\s{0,31}\)$/;
+var hslColorRegex = /^hsl\(\s{0,31}[\-\.]?\d+\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+%\s{0,31}\)|hsla\(\s{0,31}[\-\.]?\d+\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+%\s{0,31},\s{0,31}\.?\d+\s{0,31}\)$/i;
 var identifierRegex = /^(\-[a-z0-9_][a-z0-9\-_]*|[a-z][a-z0-9\-_]*)$/i;
 var namedEntityRegex = /^[a-z]+$/i;
 var prefixRegex = /^-([a-z0-9]|-)*$/i;
-var rgbColorRegex = /^rgb\(\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31}\)|rgba\(\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\.\d]+\s{0,31}\)$/;
+var rgbColorRegex = /^rgb\(\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31}\)|rgba\(\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\d]{1,3}\s{0,31},\s{0,31}[\.\d]+\s{0,31}\)$/i;
 var timingFunctionRegex = /^(cubic\-bezier|steps)\([^\)]+\)$/;
 var validTimeUnits = ['ms', 's'];
 var urlRegex = /^url\([\s\S]+\)$/i;
diff --git a/test/fixtures/big-min.css b/test/fixtures/big-min.css
index c72d406f7..9884b8586 100644
--- a/test/fixtures/big-min.css
+++ b/test/fixtures/big-min.css
@@ -189,7 +189,7 @@ body{font-size:13px;line-height:140%;color:#16212c;background:#e9edf0}
 .global{width:1000px;margin:0 auto;padding:20px 0 10px;background:#fff}
 .lmd-header{position:relative;z-index:15}
 .lmd-header #header{margin-bottom:16px}
-.deroule_edito,.deroule_fleuve,.ombre_section,.une_edito{-webkit-box-shadow:0 6px 6px -6px rgba(202,205,209,1);-moz-box-shadow:0 6px 6px -6px rgba(202,205,209,1);box-shadow:0 6px 6px -6px rgba(202,205,209,1);padding-top:0;margin-bottom:16px;margin-top:16px;overflow:hidden}
+.deroule_edito,.deroule_fleuve,.ombre_section,.une_edito{-webkit-box-shadow:0 6px 6px -6px #cacdd1;-moz-box-shadow:0 6px 6px -6px #cacdd1;box-shadow:0 6px 6px -6px #cacdd1;padding-top:0;margin-bottom:16px;margin-top:16px;overflow:hidden}
 a{color:#036;text-decoration:none;cursor:pointer}
 .bg_fonce a{opacity:.85}
 .obf{cursor:pointer;color:#036}
diff --git a/test/integration-test.js b/test/integration-test.js
index a547f4ecd..54002ec9e 100644
--- a/test/integration-test.js
+++ b/test/integration-test.js
@@ -158,9 +158,13 @@ vows.describe('integration tests')
         'a{text-shadow:rgb(255,0,1) 1px 1px}',
         'a{text-shadow:#ff0001 1px 1px}'
       ],
-      'after rgba': [
+      'after rgba #1': [
+        'a{text-shadow:rgba(255,0,0,.1) 0 1px}',
+        'a{text-shadow:rgba(255,0,0,.1) 0 1px}'
+      ],
+      'after rgba #2': [
         'a{text-shadow:rgba(255,0,0,1) 0 1px}',
-        'a{text-shadow:rgba(255,0,0,1) 0 1px}'
+        'a{text-shadow:red 0 1px}'
       ],
       'after hsl': [
         'a{text-shadow:hsl(240,100%,40%) -1px 1px}',
@@ -215,8 +219,8 @@ vows.describe('integration tests')
         'a{text-shadow:#ff0001 1px 1px}'
       ],
       'after rgba': [
-        'a{text-shadow:rgba(255,0,0,1) 0 1px}',
-        'a{text-shadow:rgba(255,0,0,1) 0 1px}'
+        'a{text-shadow:rgba(255,0,0,.1) 0 1px}',
+        'a{text-shadow:rgba(255,0,0,.1) 0 1px}'
       ],
       'after hsl': [
         'a{text-shadow:hsl(240,100%,40%) -1px 1px}',
@@ -695,8 +699,8 @@ vows.describe('integration tests')
         'a{-webkit-box-shadow:0 0;-moz-box-shadow:0 0}'
       ],
       'zero as .0 #1': [
-        'a{color:rgba(0,0,.0,1)}',
-        'a{color:rgba(0,0,0,1)}'
+        'a{color:rgba(0,0,.0,.1)}',
+        'a{color:rgba(0,0,0,.1)}'
       ],
       'zero as .0 #2': [
         'body{margin:.0}',