Adds hierarchy separator style.

src/assets/scss/_post.scss

@@ -508,6 +508,9 @@
                             color: #cbcbcb;
                             margin: 0 8px;    
                         }
+                        .hierarchy-separator {
+                            color: #cbcbcb;  
+                        }
                         .metadata-type-textarea {
                             .multivalue-separator {
                                 display: block;