diff --git a/docs/assets/css/bootstrap.css b/docs/assets/css/bootstrap.css
index ed8002e207..a9cd5ae4ad 100644
--- a/docs/assets/css/bootstrap.css
+++ b/docs/assets/css/bootstrap.css
@@ -2616,7 +2616,7 @@ button.close {
   -webkit-border-radius: 4px;
      -moz-border-radius: 4px;
           border-radius: 4px;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffffff', endColorstr='#e6e6e6', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffffffff', endColorstr='#ffe6e6e6', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
   *zoom: 1;
   -webkit-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
@@ -2757,7 +2757,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #0055cc #0055cc #003580;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#0088cc', endColorstr='#0055cc', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff0088cc', endColorstr='#ff0055cc', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -2787,7 +2787,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #f89406 #f89406 #ad6704;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#fbb450', endColorstr='#f89406', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#fffbb450', endColorstr='#fff89406', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -2817,7 +2817,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #bd362f #bd362f #802420;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ee5f5b', endColorstr='#bd362f', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffee5f5b', endColorstr='#ffbd362f', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -2847,7 +2847,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #51a351 #51a351 #387038;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#62c462', endColorstr='#51a351', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff62c462', endColorstr='#ff51a351', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -2877,7 +2877,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #2f96b4 #2f96b4 #1f6377;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#5bc0de', endColorstr='#2f96b4', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff5bc0de', endColorstr='#ff2f96b4', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -2907,7 +2907,7 @@ button.close {
   background-repeat: repeat-x;
   border-color: #222222 #222222 #000000;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#555555', endColorstr='#222222', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff555555', endColorstr='#ff222222', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
 }
 
@@ -3602,7 +3602,7 @@ input[type="submit"].btn.btn-mini {
   -webkit-border-radius: 4px;
      -moz-border-radius: 4px;
           border-radius: 4px;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#333333', endColorstr='#222222', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff333333', endColorstr='#ff222222', GradientType=0);
   -webkit-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
      -moz-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
           box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
@@ -3868,7 +3868,7 @@ input[type="submit"].btn.btn-mini {
   background-repeat: repeat-x;
   border-color: #222222 #222222 #000000;
   border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#333333', endColorstr='#222222', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff333333', endColorstr='#ff222222', GradientType=0);
   filter: progid:dximagetransform.microsoft.gradient(enabled=false);
   -webkit-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1), 0 1px 0 rgba(255, 255, 255, 0.075);
      -moz-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1), 0 1px 0 rgba(255, 255, 255, 0.075);
@@ -4000,7 +4000,7 @@ input[type="submit"].btn.btn-mini {
   -webkit-border-radius: 3px;
      -moz-border-radius: 3px;
           border-radius: 3px;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffffff', endColorstr='#f5f5f5', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffffffff', endColorstr='#fff5f5f5', GradientType=0);
   -webkit-box-shadow: inset 0 1px 0 #ffffff;
      -moz-box-shadow: inset 0 1px 0 #ffffff;
           box-shadow: inset 0 1px 0 #ffffff;
@@ -4664,7 +4664,7 @@ a.badge:hover {
   -webkit-border-radius: 4px;
      -moz-border-radius: 4px;
           border-radius: 4px;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#f5f5f5', endColorstr='#f9f9f9', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#fff5f5f5', endColorstr='#fff9f9f9', GradientType=0);
   -webkit-box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
      -moz-box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
           box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
@@ -4685,7 +4685,7 @@ a.badge:hover {
   background-image: linear-gradient(top, #149bdf, #0480be);
   background-image: -ms-linear-gradient(top, #149bdf, #0480be);
   background-repeat: repeat-x;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#149bdf', endColorstr='#0480be', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff149bdf', endColorstr='#ff0480be', GradientType=0);
   -webkit-box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.15);
      -moz-box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.15);
           box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.15);
@@ -4731,7 +4731,7 @@ a.badge:hover {
   background-image: -o-linear-gradient(top, #ee5f5b, #c43c35);
   background-image: linear-gradient(top, #ee5f5b, #c43c35);
   background-repeat: repeat-x;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ee5f5b', endColorstr='#c43c35', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffee5f5b', endColorstr='#ffc43c35', GradientType=0);
 }
 
 .progress-danger.progress-striped .bar {
@@ -4753,7 +4753,7 @@ a.badge:hover {
   background-image: -o-linear-gradient(top, #62c462, #57a957);
   background-image: linear-gradient(top, #62c462, #57a957);
   background-repeat: repeat-x;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#62c462', endColorstr='#57a957', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff62c462', endColorstr='#ff57a957', GradientType=0);
 }
 
 .progress-success.progress-striped .bar {
@@ -4775,7 +4775,7 @@ a.badge:hover {
   background-image: -o-linear-gradient(top, #5bc0de, #339bb9);
   background-image: linear-gradient(top, #5bc0de, #339bb9);
   background-repeat: repeat-x;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#5bc0de', endColorstr='#339bb9', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ff5bc0de', endColorstr='#ff339bb9', GradientType=0);
 }
 
 .progress-info.progress-striped .bar {
@@ -4797,7 +4797,7 @@ a.badge:hover {
   background-image: -o-linear-gradient(top, #fbb450, #f89406);
   background-image: linear-gradient(top, #fbb450, #f89406);
   background-repeat: repeat-x;
-  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#fbb450', endColorstr='#f89406', GradientType=0);
+  filter: progid:dximagetransform.microsoft.gradient(startColorstr='#fffbb450', endColorstr='#fff89406', GradientType=0);
 }
 
 .progress-warning.progress-striped .bar {
diff --git a/less/mixins.less b/less/mixins.less
index c3b57ed142..4f204d1af7 100644
--- a/less/mixins.less
+++ b/less/mixins.less
@@ -367,7 +367,7 @@
     background-image: -o-linear-gradient(left, @startColor, @endColor); // Opera 11.10
     background-image: linear-gradient(left, @startColor, @endColor); // Le standard
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",@startColor,@endColor)); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@startColor),argb(@endColor))); // IE9 and down
   }
   .vertical(@startColor: #555, @endColor: #333) {
     background-color: mix(@startColor, @endColor, 60%);
@@ -378,7 +378,7 @@
     background-image: -o-linear-gradient(top, @startColor, @endColor); // Opera 11.10
     background-image: linear-gradient(top, @startColor, @endColor); // The standard
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",@startColor,@endColor)); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@startColor),argb(@endColor))); // IE9 and down
   }
   .directional(@startColor: #555, @endColor: #333, @deg: 45deg) {
     background-color: @endColor;
@@ -398,7 +398,7 @@
     background-image: -o-linear-gradient(@startColor, @midColor @colorStop, @endColor);
     background-image: linear-gradient(@startColor, @midColor @colorStop, @endColor);
     background-repeat: no-repeat;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",@startColor,@endColor)); // IE9 and down, gets no color-stop at all for proper fallback
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@startColor),argb(@endColor))); // IE9 and down, gets no color-stop at all for proper fallback
   }
   .radial(@innerColor: #555, @outerColor: #333)  {
     background-color: @outerColor;