gh-9600: Fixed text being unreadable with some themes (gh-12998)

src/zen/common/styles/schemes/dark.inc.css

@@ -3,5 +3,4 @@
 % file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 color-scheme: dark;
---toolbar-color-scheme: dark;
 --zen-urlbar-outline-offset: -2px;

src/zen/common/styles/schemes/light.inc.css

@@ -3,5 +3,4 @@
 % file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 color-scheme: light;
---toolbar-color-scheme: light;
 --zen-urlbar-outline-offset: 0px;

src/zen/spaces/ZenGradientGenerator.mjs

@@ -1753,6 +1753,10 @@ export class nsZenThemePicker extends nsZenMultiWindowFeature {
           "--toolbox-textcolor",
           `rgba(${textColor[0]}, ${textColor[1]}, ${textColor[2]}, ${textColor[3]})`
         );
+        docElement.style.setProperty(
+          "--toolbar-color-scheme",
+          isDarkMode ? "dark" : "light"
+        );
       }
 
       if (!skipUpdate) {