diff --git a/Zukitre/gtk-3.0/_common.scss b/Zukitre/gtk-3.0/_common.scss
index dba27a4..2218603 100644
--- a/Zukitre/gtk-3.0/_common.scss
+++ b/Zukitre/gtk-3.0/_common.scss
@@ -1709,6 +1709,11 @@ menu,
 
   &:backdrop { background-color: $backdrop_menu_color; }
 
+  // Firefox workaround
+  .separator:not(label),
+  .csd & .separator:not(label) { color: darken($menu_color, 5%); }
+  // Firefox workaround end
+
   menuitem {
     min-height: 16px;
     min-width: 40px;
diff --git a/Zukitre/gtk-3.0/gtk-contained-dark.css b/Zukitre/gtk-3.0/gtk-contained-dark.css
index 5aefc14..5a6060e 100644
--- a/Zukitre/gtk-3.0/gtk-contained-dark.css
+++ b/Zukitre/gtk-3.0/gtk-contained-dark.css
@@ -1837,6 +1837,12 @@ menu,
   .menu:backdrop,
   .context-menu:backdrop {
     background-color: #4b626d; }
+  menu .separator:not(label), .csd menu .separator:not(label),
+  .menu .separator:not(label), .csd
+  .menu .separator:not(label),
+  .context-menu .separator:not(label), .csd
+  .context-menu .separator:not(label) {
+    color: #41545e; }
   menu menuitem,
   .menu menuitem,
   .context-menu menuitem {
diff --git a/Zukitre/gtk-3.0/gtk-contained.css b/Zukitre/gtk-3.0/gtk-contained.css
index e460e5d..ad3a892 100644
--- a/Zukitre/gtk-3.0/gtk-contained.css
+++ b/Zukitre/gtk-3.0/gtk-contained.css
@@ -1851,6 +1851,12 @@ menu,
   .menu:backdrop,
   .context-menu:backdrop {
     background-color: #F7F7F7; }
+  menu .separator:not(label), .csd menu .separator:not(label),
+  .menu .separator:not(label), .csd
+  .menu .separator:not(label),
+  .context-menu .separator:not(label), .csd
+  .context-menu .separator:not(label) {
+    color: #eaeaea; }
   menu menuitem,
   .menu menuitem,
   .context-menu menuitem {
diff --git a/Zukitwo/gtk-3.0/_common.scss b/Zukitwo/gtk-3.0/_common.scss
index 3d92c41..8863239 100644
--- a/Zukitwo/gtk-3.0/_common.scss
+++ b/Zukitwo/gtk-3.0/_common.scss
@@ -1724,6 +1724,11 @@ menu,
 
   &:backdrop { background-color: $backdrop_menu_color; }
 
+  // Firefox workaround
+  .separator:not(label),
+  .csd & .separator:not(label) { color: darken($menu_color, 5%); }
+  // Firefox workaround end
+
   menuitem {
     min-height: 16px;
     min-width: 40px;
diff --git a/Zukitwo/gtk-3.0/gtk-contained-dark.css b/Zukitwo/gtk-3.0/gtk-contained-dark.css
index e347bda..094a724 100644
--- a/Zukitwo/gtk-3.0/gtk-contained-dark.css
+++ b/Zukitwo/gtk-3.0/gtk-contained-dark.css
@@ -1840,6 +1840,12 @@ menu,
   .menu:backdrop,
   .context-menu:backdrop {
     background-color: #3e4953; }
+  menu .separator:not(label), .csd menu .separator:not(label),
+  .menu .separator:not(label), .csd
+  .menu .separator:not(label),
+  .context-menu .separator:not(label), .csd
+  .context-menu .separator:not(label) {
+    color: #333c44; }
   menu menuitem,
   .menu menuitem,
   .context-menu menuitem {
diff --git a/Zukitwo/gtk-3.0/gtk-contained.css b/Zukitwo/gtk-3.0/gtk-contained.css
index 3217ad0..48859e3 100644
--- a/Zukitwo/gtk-3.0/gtk-contained.css
+++ b/Zukitwo/gtk-3.0/gtk-contained.css
@@ -1854,6 +1854,12 @@ menu,
   .menu:backdrop,
   .context-menu:backdrop {
     background-color: #F7F7F7; }
+  menu .separator:not(label), .csd menu .separator:not(label),
+  .menu .separator:not(label), .csd
+  .menu .separator:not(label),
+  .context-menu .separator:not(label), .csd
+  .context-menu .separator:not(label) {
+    color: #eaeaea; }
   menu menuitem,
   .menu menuitem,
   .context-menu menuitem {