Fix CSS blendmode for certain blockquotes

Change-Id: Ia05000e164c5a10693de84aaa258c4883dbe06be
diff --git a/dev/scss/base/base.scss b/dev/scss/base/base.scss
index dd0d6a3..306e48d 100644
--- a/dev/scss/base/base.scss
+++ b/dev/scss/base/base.scss
@@ -94,6 +94,7 @@
     border-left-color: $dark-red;
     background-color:  $middle-red;
     color:             $nearly-white;
+    mix-blend-mode:    multiply;
   }
 }