Make only images greyscale. Added chrome support

boards/static/css/base.css

@@ -153,6 +153,7 b' textarea, input {'
     opacity: 1;
 }
 
-.monochrome {
+.monochrome > .image > .thumb > img {
     filter: grayscale(100%);
-}
  No newline at end of file
+    -webkit-filter: grayscale(100%);
+}