--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -91,16 +91,20 @@ CSS_KEY(-moz-mac-defaultbuttontext, _moz
 CSS_KEY(-moz-mac-focusring, _moz_mac_focusring)
 CSS_KEY(-moz-mac-fullscreen-button, _moz_mac_fullscreen_button)
 CSS_KEY(-moz-mac-menuselect, _moz_mac_menuselect)
 CSS_KEY(-moz-mac-menushadow, _moz_mac_menushadow)
 CSS_KEY(-moz-mac-menutextdisable, _moz_mac_menutextdisable)
 CSS_KEY(-moz-mac-menutextselect, _moz_mac_menutextselect)
 CSS_KEY(-moz-mac-disabledtoolbartext, _moz_mac_disabledtoolbartext)
 CSS_KEY(-moz-mac-secondaryhighlight, _moz_mac_secondaryhighlight)
+CSS_KEY(-moz-mac-menuitem, _moz_mac_menuitem)
+CSS_KEY(-moz-mac-active-menuitem, _moz_mac_active_menuitem)
+CSS_KEY(-moz-mac-menupopup, _moz_mac_menupopup)
+CSS_KEY(-moz-mac-tooltip, _moz_mac_tooltip)
 CSS_KEY(-moz-max-content, _moz_max_content)
 CSS_KEY(-moz-menuhover, _moz_menuhover)
 CSS_KEY(-moz-menuhovertext, _moz_menuhovertext)
 CSS_KEY(-moz-menubartext, _moz_menubartext)
 CSS_KEY(-moz-menubarhovertext, _moz_menubarhovertext)
 CSS_KEY(-moz-middle-with-baseline, _moz_middle_with_baseline)
 CSS_KEY(-moz-min-content, _moz_min_content)
 CSS_KEY(-moz-nativehyperlinktext, _moz_nativehyperlinktext)

--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -1124,16 +1124,25 @@ const KTableEntry nsCSSProps::kColorKTab
   { eCSSKeyword__moz_mac_defaultbuttontext, LookAndFeel::eColorID__moz_mac_defaultbuttontext },
   { eCSSKeyword__moz_mac_focusring, LookAndFeel::eColorID__moz_mac_focusring },
   { eCSSKeyword__moz_mac_menuselect, LookAndFeel::eColorID__moz_mac_menuselect },
   { eCSSKeyword__moz_mac_menushadow, LookAndFeel::eColorID__moz_mac_menushadow },
   { eCSSKeyword__moz_mac_menutextdisable, LookAndFeel::eColorID__moz_mac_menutextdisable },
   { eCSSKeyword__moz_mac_menutextselect, LookAndFeel::eColorID__moz_mac_menutextselect },
   { eCSSKeyword__moz_mac_disabledtoolbartext, LookAndFeel::eColorID__moz_mac_disabledtoolbartext },
   { eCSSKeyword__moz_mac_secondaryhighlight, LookAndFeel::eColorID__moz_mac_secondaryhighlight },
+  { eCSSKeyword__moz_mac_vibrancy_light, LookAndFeel::eColorID__moz_mac_vibrancy_light },
+  { eCSSKeyword__moz_mac_vibrancy_dark, LookAndFeel::eColorID__moz_mac_vibrancy_dark },
+  { eCSSKeyword__moz_mac_menuitem, LookAndFeel::eColorID__moz_mac_menuitem },
+  { eCSSKeyword__moz_mac_active_menuitem, LookAndFeel::eColorID__moz_mac_active_menuitem },
+  { eCSSKeyword__moz_mac_menupopup, LookAndFeel::eColorID__moz_mac_menupopup },
+  { eCSSKeyword__moz_mac_source_list, LookAndFeel::eColorID__moz_mac_source_list },
+  { eCSSKeyword__moz_mac_source_list_selection, LookAndFeel::eColorID__moz_mac_source_list_selection },
+  { eCSSKeyword__moz_mac_active_source_list_selection, LookAndFeel::eColorID__moz_mac_active_source_list_selection },
+  { eCSSKeyword__moz_mac_tooltip, LookAndFeel::eColorID__moz_mac_tooltip },
   { eCSSKeyword__moz_menuhover, LookAndFeel::eColorID__moz_menuhover },
   { eCSSKeyword__moz_menuhovertext, LookAndFeel::eColorID__moz_menuhovertext },
   { eCSSKeyword__moz_menubartext, LookAndFeel::eColorID__moz_menubartext },
   { eCSSKeyword__moz_menubarhovertext, LookAndFeel::eColorID__moz_menubarhovertext },
   { eCSSKeyword__moz_oddtreerow, LookAndFeel::eColorID__moz_oddtreerow },
   { eCSSKeyword__moz_visitedhyperlinktext, NS_COLOR_MOZ_VISITEDHYPERLINKTEXT },
   { eCSSKeyword_currentcolor, NS_COLOR_CURRENTCOLOR },
   { eCSSKeyword__moz_win_accentcolor, LookAndFeel::eColorID__moz_win_accentcolor },

--- a/widget/LookAndFeel.h
+++ b/widget/LookAndFeel.h
@@ -151,16 +151,28 @@ public:
     eColorID__moz_mac_menutextdisable,
     //colour used to display text while mouse is over a menu item
     eColorID__moz_mac_menutextselect,
     // text color of disabled text on toolbars
     eColorID__moz_mac_disabledtoolbartext,
     //inactive light hightlight
     eColorID__moz_mac_secondaryhighlight,
 
+    // Font smoothing background colors needed by the Mac OS X theme, based
+    // on -moz-appearance names
+    eColorID__moz_mac_vibrancy_light,
+    eColorID__moz_mac_vibrancy_dark,
+    eColorID__moz_mac_menupopup,
+    eColorID__moz_mac_menuitem,
+    eColorID__moz_mac_active_menuitem,
+    eColorID__moz_mac_source_list,
+    eColorID__moz_mac_source_list_selection,
+    eColorID__moz_mac_active_source_list_selection,
+    eColorID__moz_mac_tooltip,
+
     // vista rebars
 
     // accent color for title bar
     eColorID__moz_win_accentcolor,
     // color from drawing text over the accent color
     eColorID__moz_win_accentcolortext,
     // media rebar text
     eColorID__moz_win_mediatext,

--- a/widget/cocoa/nsLookAndFeel.mm
+++ b/widget/cocoa/nsLookAndFeel.mm
@@ -301,23 +301,51 @@ nsLookAndFeel::NativeGetColor(ColorID aI
     case eColorID__moz_oddtreerow:
       // Background color of odd list rows.
       aColor = GetColorFromNSColor([[NSColor controlAlternatingRowBackgroundColors] objectAtIndex:1]);
       break;
     case eColorID__moz_nativehyperlinktext:
       // There appears to be no available system defined color. HARDCODING to the appropriate color.
       aColor = NS_RGB(0x14,0x4F,0xAE);
       break;
+    // The following colors are supposed to be used as font-smoothing background
+    // colors, in the chrome-only -moz-font-smoothing-background-color property.
+    // This property is used for text on "vibrant" -moz-appearances.
+    // The colors have been obtained from the system on 10.12.6 using the
+    // program at https://bugzilla.mozilla.org/attachment.cgi?id=8907533 .
+    // We could obtain them at runtime, but doing so may be expensive and
+    // requires the use of the private API
+    // -[NSVisualEffectView fontSmoothingBackgroundColor].
+    case eColorID__moz_mac_vibrancy_light:
+    case eColorID__moz_mac_source_list:
+    case eColorID__moz_mac_tooltip:
+      aColor = NS_RGB(0xf7,0xf7,0xf7);
+      break;
+    case eColorID__moz_mac_vibrancy_dark:
+      aColor = NS_RGB(0x28,0x28,0x28);
+      break;
+    case eColorID__moz_mac_menupopup:
+    case eColorID__moz_mac_menuitem:
+      aColor = NS_RGB(0xe6,0xe6,0xe6);
+      break;
+    case eColorID__moz_mac_source_list_selection:
+      aColor = NS_RGB(0xc8,0xc8,0xc8);
+      break;
+    case eColorID__moz_mac_active_menuitem:
+    case eColorID__moz_mac_active_source_list_selection:
+      aColor = [NSColor currentControlTint] == NSGraphiteControlTint
+        ? NS_RGB(0xa0,0xa0,0xa0) : NS_RGB(0x0a,0x64,0xdc);
+      break;
     default:
       NS_WARNING("Someone asked nsILookAndFeel for a color I don't know about");
       aColor = NS_RGB(0xff,0xff,0xff);
       res = NS_ERROR_FAILURE;
       break;
     }
-  
+
   return res;
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
 
 nsresult
 nsLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
 {

--- a/widget/nsXPLookAndFeel.cpp
+++ b/widget/nsXPLookAndFeel.cpp
@@ -139,21 +139,21 @@ nsLookAndFeelFloatPref nsXPLookAndFeel::
   { "ui.caretAspectRatio",
     eFloatID_CaretAspectRatio,
     false, 0 },
 };
 
 
 // This array MUST be kept in the same order as the color list in LookAndFeel.h.
 /* XXX If you add any strings longer than
- * "ui.IMESelectedConvertedTextBackground"
+ * "ui.-moz-mac-active-source-list-selection"
  * to the following array then you MUST update the
  * sizes of the sColorPrefs array in nsXPLookAndFeel.h
  */
-const char nsXPLookAndFeel::sColorPrefs[][38] =
+const char nsXPLookAndFeel::sColorPrefs[][41] =
 {
   "ui.windowBackground",
   "ui.windowForeground",
   "ui.widgetBackground",
   "ui.widgetForeground",
   "ui.widgetSelectBackground",
   "ui.widgetSelectForeground",
   "ui.widget3DHighlight",
@@ -232,16 +232,25 @@ const char nsXPLookAndFeel::sColorPrefs[
   "ui.-moz-mac-defaultbuttontext",
   "ui.-moz-mac-focusring",
   "ui.-moz-mac-menuselect",
   "ui.-moz-mac-menushadow",
   "ui.-moz-mac-menutextdisable",
   "ui.-moz-mac-menutextselect",
   "ui.-moz_mac_disabledtoolbartext",
   "ui.-moz-mac-secondaryhighlight",
+  "ui.-moz-mac-vibrancy-light",
+  "ui.-moz-mac-vibrancy-dark",
+  "ui.-moz-mac-menupopup",
+  "ui.-moz-mac-menuitem",
+  "ui.-moz-mac-active-menuitem",
+  "ui.-moz-mac-source-list",
+  "ui.-moz-mac-source-list-selection",
+  "ui.-moz-mac-active-source-list-selection",
+  "ui.-moz-mac-tooltip",
   "ui.-moz-win-mediatext",
   "ui.-moz-win-communicationstext",
   "ui.-moz-nativehyperlinktext",
   "ui.-moz-comboboxtext",
   "ui.-moz-combobox"
 };
 
 int32_t nsXPLookAndFeel::sCachedColors[LookAndFeel::eColorID_LAST_COLOR] = {0};
@@ -653,16 +662,34 @@ nsXPLookAndFeel::GetStandinForNativeColo
     case eColorID__moz_mac_menutextdisable:
       result = NS_RGB(0x88, 0x88, 0x88); break;
     case eColorID__moz_mac_menutextselect:
       result = NS_RGB(0xFF, 0xFF, 0xFF); break;
     case eColorID__moz_mac_disabledtoolbartext:
       result = NS_RGB(0x3F, 0x3F, 0x3F); break;
     case eColorID__moz_mac_secondaryhighlight:
       result = NS_RGB(0xD4, 0xD4, 0xD4); break;
+    case eColorID__moz_mac_vibrancy_light:
+      result = NS_RGB(0xf7, 0xf7, 0xf7); break;
+    case eColorID__moz_mac_vibrancy_dark:
+      result = NS_RGB(0x28, 0x28, 0x28); break;
+    case eColorID__moz_mac_menupopup:
+      result = NS_RGB(0xe6, 0xe6, 0xe6); break;
+    case eColorID__moz_mac_menuitem:
+      result = NS_RGB(0xe6, 0xe6, 0xe6); break;
+    case eColorID__moz_mac_active_menuitem:
+      result = NS_RGB(0x0a, 0x64, 0xdc); break;
+    case eColorID__moz_mac_source_list:
+      result = NS_RGB(0xf7, 0xf7, 0xf7); break;
+    case eColorID__moz_mac_source_list_selection:
+      result = NS_RGB(0xc8, 0xc8, 0xc8); break;
+    case eColorID__moz_mac_active_source_list_selection:
+      result = NS_RGB(0x0a, 0x64, 0xdc); break;
+    case eColorID__moz_mac_tooltip:
+      result = NS_RGB(0xf7, 0xf7, 0xf7); break;
     case eColorID__moz_win_accentcolor:
       // Seems to be the default color (hardcoded because of bug 1065998)
       result = NS_RGB(0x9E, 0x9E, 0x9E); break;
     case eColorID__moz_win_accentcolortext:
       result = NS_RGB(0x00, 0x00, 0x00); break;
     case eColorID__moz_win_mediatext:
       result = NS_RGB(0xFF, 0xFF, 0xFF); break;
     case eColorID__moz_win_communicationstext:

--- a/widget/nsXPLookAndFeel.h
+++ b/widget/nsXPLookAndFeel.h
@@ -103,17 +103,17 @@ protected:
   static void OnPrefChanged(const char* aPref, void* aClosure);
 
   static bool sInitialized;
   static nsLookAndFeelIntPref sIntPrefs[];
   static nsLookAndFeelFloatPref sFloatPrefs[];
   /* this length must not be shorter than the length of the longest string in the array
    * see nsXPLookAndFeel.cpp
    */
-  static const char sColorPrefs[][38];
+  static const char sColorPrefs[][41];
   static int32_t sCachedColors[LookAndFeel::eColorID_LAST_COLOR];
   static int32_t sCachedColorBits[COLOR_CACHE_SIZE];
   static bool sUseNativeColors;
   static bool sUseStandinsForNativeColors;
   static bool sFindbarModalHighlight;
 
   static nsXPLookAndFeel* sInstance;
   static bool sShutdown;