Specify the color space (sRGB) in all numpy.org CSS files

Fixes #gh-397.

Author: aerikpawson

static/css/casestudies.css

@@ -30,6 +30,7 @@
 
 .casestudies a {
     color: #013243 !important;
+    color space: rgb
 }
 
 .casestudies-box-title {
@@ -86,4 +87,4 @@
 
 .casestudies-underline:hover:before, .casestudies-underline:focus:before, .casestudies-underline:active:before {
     right: 0;
-}
+}