diff --git a/skin/classic/treestyletab/Linux-base.css b/skin/classic/treestyletab/Linux-base.css
index 925f3865..04ba193e 100644
--- a/skin/classic/treestyletab/Linux-base.css
+++ b/skin/classic/treestyletab/Linux-base.css
@@ -18,8 +18,8 @@
   #treestyletab-autohide-content-area-screen,
 :root[treestyletab-tabbar-position="right"]
   #treestyletab-autohide-content-area-screen  {
-	border-right: 1px solid ThreeDShadow;
-	border-left: 1px solid ThreeDShadow;
+	border-right: 1px solid var(--tst-tab-border);
+	border-left: 1px solid var(--tst-tab-border);
 }
 
 
diff --git a/skin/classic/treestyletab/base-colors.css b/skin/classic/treestyletab/base-colors.css
index 5efa7710..fbfb9ffe 100644
--- a/skin/classic/treestyletab/base-colors.css
+++ b/skin/classic/treestyletab/base-colors.css
@@ -37,15 +37,17 @@
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 
 :root {
-	--tab-surface: -moz-dialog;
-	--tab-text: -moz-dialogtext;
-	--tab-surface-hover: ThreeDHighlight;
-	--tab-dropmarker: -moz-dialogtext;
+	--tst-tab-surface: -moz-dialog;
+	--tst-tab-text: -moz-dialogtext;
+	--tst-tab-border: ThreeDShadow;
+	--tst-tab-surface-hover: ThreeDHighlight;
+	--tst-tab-dropmarker: -moz-dialogtext;
 }
 
 :root[devtoolstheme="dark"] {
-	--tab-surface: #39424D;
-	--tab-text: white;
-	--tab-surface-hover: #49525D;
-	--tab-dropmarker: white;
+	--tst-tab-surface: #39424D;
+	--tst-tab-text: white;
+	--tst-tab-border: #5f6670;
+	--tst-tab-surface-hover: #49525D;
+	--tst-tab-dropmarker: white;
 }
\ No newline at end of file
diff --git a/skin/classic/treestyletab/base.css b/skin/classic/treestyletab/base.css
index 8c70d1ca..d164eb4f 100644
--- a/skin/classic/treestyletab/base.css
+++ b/skin/classic/treestyletab/base.css
@@ -51,12 +51,12 @@
 	-moz-border-left-colors: none !important;
 	border-radius: 0;
 	-moz-border-radius: 0;
-	border-top: 1px solid ThreeDShadow !important;
-	background: var(--tab-surface) !important;
+	border-top: 1px solid var(--tst-tab-border) !important;
+	background: var(--tst-tab-surface) !important;
 }
 .tabbrowser-tabs[treestyletab-mode="vertical"] .tabs-newtab-button:hover,
 .treestyletab-tabbar-toolbar[treestyletab-mode="vertical"] > toolbarbutton:hover {
-	background: var(--tab-surface-hover) !important;
+	background: var(--tst-tab-surface-hover) !important;
 }
 
 /* for Mac OS X */
@@ -81,7 +81,7 @@
 }
 .treestyletab-tabbar-toolbar[treestyletab-mode="vertical"] > *:not(toolbarpaletteitem) {
 	-moz-border-top-colors: none !important;
-	border-top: 1px solid ThreeDShadow !important;
+	border-top: 1px solid var(--tst-tab-border) !important;
 }
 .treestyletab-tabbar-toolbar[treestyletab-mode="vertical"] > *:first-child,
 .treestyletab-tabbar-toolbar[treestyletab-mode="vertical"] > *:first-child[hidden="true"] + *:not(toolbarpaletteitem),
@@ -109,7 +109,7 @@
 .tabbrowser-tabs[treestyletab-mode="vertical"]
   .tabbrowser-arrowscrollbox .tabs-newtab-button {
 	border: 0 none !important;
-	border-bottom: 1px solid ThreeDShadow !important;
+	border-bottom: 1px solid var(--tst-tab-border) !important;
 	border-radius: 0 0 3px 3px;
 	-moz-border-radius: 0 0 3px 3px;
 }
diff --git a/skin/classic/treestyletab/tmp.css b/skin/classic/treestyletab/tmp.css
index 07dd4a07..bc7f0b4d 100644
--- a/skin/classic/treestyletab/tmp.css
+++ b/skin/classic/treestyletab/tmp.css
@@ -45,7 +45,7 @@
 	-moz-border-right-colors: none !important;
 	-moz-border-bottom-colors: none !important;
 	-moz-border-left-colors: none !important;
-	border-top: 1px solid ThreeDShadow !important;
+	border-top: 1px solid var(--tst-tab-border) !important;
 	background: -moz-dialog !important;
 }
 
diff --git a/skin/classic/treestyletab/ui-base.css b/skin/classic/treestyletab/ui-base.css
index cfdb1a01..4f6f33f6 100644
--- a/skin/classic/treestyletab/ui-base.css
+++ b/skin/classic/treestyletab/ui-base.css
@@ -28,7 +28,7 @@
   .tabbrowser-tab[treestyletab-drop-position="before"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-tabbar-position="bottom"]
   .tabbrowser-tab[treestyletab-drop-position="before"]:not([visuallyselected="true"]):hover {
-	-moz-border-left-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-left-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 .tabbrowser-tabs[treestyletab-tabbar-position="bottom"]
@@ -39,7 +39,7 @@
   .tabbrowser-tab[treestyletab-drop-position="after"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-tabbar-position="bottom"]
   .tabbrowser-tab[treestyletab-drop-position="after"]:not([visuallyselected="true"]):hover {
-	-moz-border-right-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-right-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 
@@ -67,10 +67,10 @@
   .tabbrowser-tab[treestyletab-drop-position="self"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-tabbar-position="bottom"][treestyletab-style]
   .tabbrowser-tab[treestyletab-drop-position="self"]:not([visuallyselected="true"]):hover {
-	-moz-border-top-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
-	-moz-border-right-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
-	-moz-border-bottom-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
-	-moz-border-left-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-top-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
+	-moz-border-right-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
+	-moz-border-bottom-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
+	-moz-border-left-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 .tabbrowser-tabs[treestyletab-mode="vertical"]:not([treestyletab-style])
@@ -108,7 +108,7 @@
   .tabbrowser-tab:first-child:not([pinned="true"])[treestyletab-drop-position="before"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style][treestyletab-firsttab-border="true"]
   .tabbrowser-tab:first-child:not([pinned="true"])[treestyletab-drop-position="before"]:not([visuallyselected="true"]):hover {
-	-moz-border-top-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-top-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
@@ -119,7 +119,7 @@
   .tabbrowser-tab:not([pinned="true"])[treestyletab-drop-position="after"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
   .tabbrowser-tab:not([pinned="true"])[treestyletab-drop-position="after"]:not([visuallyselected="true"]):hover {
-	-moz-border-bottom-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-bottom-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
@@ -130,7 +130,7 @@
   .tabbrowser-tab[pinned="true"][treestyletab-drop-position="before"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
   .tabbrowser-tab[pinned="true"][treestyletab-drop-position="before"]:not([visuallyselected="true"]):hover {
-	-moz-border-left-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-left-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
@@ -141,7 +141,7 @@
   .tabbrowser-tab[pinned="true"][treestyletab-drop-position="after"]:not([visuallyselected="true"]),
 .tabbrowser-tabs[treestyletab-mode="vertical"][treestyletab-style]
   .tabbrowser-tab[pinned="true"][treestyletab-drop-position="after"]:not([visuallyselected="true"]):hover {
-	-moz-border-right-colors: var(--tab-dropmarker) var(--tab-dropmarker) !important;
+	-moz-border-right-colors: var(--tst-tab-dropmarker) var(--tst-tab-dropmarker) !important;
 }
 
 
@@ -159,7 +159,7 @@
 .tabbrowser-tabs[treestyletab-tabbar-position="top"]
   .tabbrowser-tab[treestyletab-drop-position="self"]:not([visuallyselected="true"]):hover
   .tab-content {
-	outline: 2px var(--tab-dropmarker) solid !important;
+	outline: 2px var(--tst-tab-dropmarker) solid !important;
 }
 
 
@@ -195,16 +195,16 @@ tabbrowser[treestyletab-drop-position] {
 	opacity: 0.5;
 }
 tabbrowser[treestyletab-drop-position="top"]:not([treestyletab-tabbar-position="top"]) {
-	border-top-color: var(--tab-dropmarker) !important;
+	border-top-color: var(--tst-tab-dropmarker) !important;
 }
 tabbrowser[treestyletab-drop-position="right"]:not([treestyletab-tabbar-position="right"]) {
-	border-right-color: var(--tab-dropmarker) !important;
+	border-right-color: var(--tst-tab-dropmarker) !important;
 }
 tabbrowser[treestyletab-drop-position="bottom"]:not([treestyletab-tabbar-position="bottom"]) {
-	border-bottom-color: var(--tab-dropmarker) !important;
+	border-bottom-color: var(--tst-tab-dropmarker) !important;
 }
 tabbrowser[treestyletab-drop-position="left"]:not([treestyletab-tabbar-position="left"]) {
-	border-left-color: var(--tab-dropmarker) !important;
+	border-left-color: var(--tst-tab-dropmarker) !important;
 }
 
 
@@ -275,15 +275,18 @@ tabbrowser[treestyletab-drop-position="left"]:not([treestyletab-tabbar-position=
 
 tabbrowser[treestyletab-tabbar-position="left"]
   .treestyletab-tabbar-toggler {
-	border-right: 1px solid ThreeDShadow;
+	border-right: 1px solid;
+	border-right-color: var(--tst-tab-border);
 }
 tabbrowser[treestyletab-tabbar-position="right"]
   .treestyletab-tabbar-toggler {
-	border-left: 1px solid ThreeDShadow;
+	border-left: 1px solid;
+	border-left-color: var(--tst-tab-border);
 }
 tabbrowser[treestyletab-tabbar-position="bottom"]
   .treestyletab-tabbar-toggler {
-	border-top: 1px solid ThreeDShadow;
+	border-top: 1px solid;
+	border-top-color: var(--tst-tab-border);
 }
 .treestyletab-tabbar-toolbar[treestyletab-tabbar-autohide]
   #treestyletab-tabbar-resizer-box {