Bug 1871375 - Provide some subtle color feedback on inactive windows for our default themes. r=dao,desktop-theme-reviewers

This is a bit subtle but I think it's worth it. The frame colors are
changed from hex to rgb to make the parallel with browser-custom-colors
clearer.

Depends on D197077

Differential Revision: https://phabricator.services.mozilla.com/D197078

browser/themes/addons/dark/manifest.json

@@ -20,7 +20,8 @@
       "tab_selected": "rgb(66,65,77)",
       "tab_text": "rgb(251,251,254)",
       "icons": "rgb(251,251,254)",
-      "frame": "#1c1b22",
+      "frame": "rgb(28, 27, 34)",
+      "frame_inactive": "rgb(31, 30, 37)",
       "popup": "rgb(66,65,77)",
       "popup_text": "rgb(251,251,254)",
       "popup_border": "rgb(82,82,94)",

browser/themes/addons/light/manifest.json

@@ -20,7 +20,8 @@
       "tab_selected": "#fff",
       "tab_text": "rgb(21,20,26)",
       "icons": "rgb(91,91,102)",
-      "frame": "#f0f0f4",
+      "frame": "rgb(240, 240, 244)",
+      "frame_inactive": "rgb(235, 235, 239)",
       "popup": "#fff",
       "popup_text": "rgb(21,20,26)",
       "popup_border": "rgb(240,240,244)",
@@ -30,8 +31,8 @@
       "toolbar": "#f9f9fb",
       "toolbar_top_separator": "transparent",
       "toolbar_bottom_separator": "#ccc",
-      "toolbar_field": "#f0f0f4",
-      "toolbar_field_text": "rgb(21,20,26)",
+      "toolbar_field": "rgb(240, 240, 244)",
+      "toolbar_field_text": "rgb(21, 20, 26)",
       "toolbar_field_border": "transparent",
       "toolbar_field_focus": "white",
       "toolbar_text": "rgb(21,20,26)",

browser/themes/shared/browser-custom-colors.css

@@ -55,6 +55,10 @@
     --toolbox-non-lwt-bgcolor-inactive: var(--toolbox-non-lwt-bgcolor);
     --toolbox-non-lwt-textcolor-inactive: var(--toolbox-non-lwt-textcolor);
 
+    &:where([tabsintitlebar]) {
+      --toolbox-non-lwt-bgcolor-inactive: light-dark(rgb(235, 235, 239), rgb(31, 30, 37));
+    }
+
     --toolbar-color: light-dark(rgb(21, 20, 26), rgb(251, 251, 254));
     --toolbar-non-lwt-bgcolor: light-dark(#f9f9fb, rgb(43, 42, 51));
     --toolbar-non-lwt-textcolor: var(--toolbar-color);