Issue #3478920 by xmacinfo: Adjust nav menu right border color

css/xnavigation.css

@@ -43,6 +43,11 @@
   border-top-color: #43352C;
 }
 
+#admin-toolbar #menu-builder.xnavigation-blackstone,
+#admin-toolbar .xnavigation-blackstone + nav#menu-footer {
+  border-right-color: #43352C;
+}
+
 /* Slate */
 
 #admin-toolbar .xnavigation-slate .toolbar-menu--level-2 {
@@ -89,3 +94,8 @@
 #admin-toolbar .xnavigation-slate + nav {
   border-top-color: #2D4459;
 }
+
+#admin-toolbar #menu-builder.xnavigation-slate,
+#admin-toolbar .xnavigation-slate + nav#menu-footer {
+  border-right-color: #2D4459;
+}