diff --git a/src/cascadia/TerminalApp/App.xaml b/src/cascadia/TerminalApp/App.xaml
index 01b315644cc..7dabb689a3c 100644
--- a/src/cascadia/TerminalApp/App.xaml
+++ b/src/cascadia/TerminalApp/App.xaml
@@ -149,7 +149,7 @@
                                 See GH #12356 for more history on the subject.
                             -->
                             <SolidColorBrush x:Key="TabViewBackground"
-                                             Color="#2e2e2e" />
+                                             Color="#0a0a0a" />
 
                             <StaticResource x:Key="UnfocusedBorderBrush"
                                             ResourceKey="ApplicationPageBackgroundThemeBrush" />
@@ -165,7 +165,7 @@
                                 GH #12398 has more history on this value, as well as GH #12400
                             -->
                             <SolidColorBrush x:Key="TabViewBackground"
-                                             Color="#e8e8e8" />
+                                             Color="#dadada" />
 
                             <StaticResource x:Key="UnfocusedBorderBrush"
                                             ResourceKey="ApplicationPageBackgroundThemeBrush" />
diff --git a/src/cascadia/TerminalSettingsModel/defaults.json b/src/cascadia/TerminalSettingsModel/defaults.json
index 9f1a3ef4f46..76d5f4b3bd1 100644
--- a/src/cascadia/TerminalSettingsModel/defaults.json
+++ b/src/cascadia/TerminalSettingsModel/defaults.json
@@ -26,7 +26,7 @@
     // Miscellaneous
     "confirmCloseAllTabs": true,
     "startOnUserLogin": false,
-    "theme": "dark",
+    "theme": "system",
     "snapToGridOnResize": true,
     "disableAnimations": false,
     "startupActions": "",
@@ -283,44 +283,20 @@
     "themes": [
         {
             "name": "light",
-            "window":
-            {
+            "window":{
                 "applicationTheme": "light"
-            },
-            "tab":
-            {
-                "background": "terminalBackground",
-                "unfocusedBackground": "#00000000"
-            },
-            "tabRow":
-            {
-                "unfocusedBackground": "#FFFFFFFF"
             }
         },
         {
             "name": "dark",
-            "window":
-            {
+            "window":{
                 "applicationTheme": "dark"
-            },
-            "tab":
-            {
-                "background": "terminalBackground",
-                "unfocusedBackground": "#00000000",
-            },
-            "tabRow":
-            {
-                "unfocusedBackground": "#333333FF"
             }
         },
         {
             "name": "system",
             "window":{
                 "applicationTheme": "system"
-            },
-            "tab":{
-                "background": "terminalBackground",
-                "unfocusedBackground": "#00000000",
             }
         }
     ],