diff --git a/shell/plugins/model-usage/Widget.qml b/shell/plugins/model-usage/Widget.qml
index 497f4e3b..59583b9e 100644
--- a/shell/plugins/model-usage/Widget.qml
+++ b/shell/plugins/model-usage/Widget.qml
@@ -175,16 +175,16 @@ BarWidget {
       + 0.0722 * colorChannelLuminance(color.b)
   }
 
-  function codexIconSource() {
-    return colorLuminance(foreground) < 0.5
+  function codexIconSource(surfaceColor) {
+    return colorLuminance(surfaceColor || Color.background) >= 0.5
       ? Qt.resolvedUrl("assets/codex-light.svg")
       : Qt.resolvedUrl("assets/codex.svg")
   }
 
-  function iconSourceForProvider(provider) {
+  function iconSourceForProvider(provider, surfaceColor) {
     if (!provider) return ""
     if (provider.providerId === "claude") return Qt.resolvedUrl("assets/claude.svg")
-    if (provider.providerId === "codex") return codexIconSource()
+    if (provider.providerId === "codex") return codexIconSource(surfaceColor)
     return ""
   }
 
@@ -350,7 +350,7 @@ BarWidget {
       spacing: 4
 
       Image {
-        source: root.iconSourceForProvider(chip.modelData)
+        source: root.iconSourceForProvider(chip.modelData, root.bar ? root.bar.background : Color.bar.background)
         width: 13
         height: 13
         sourceSize.width: 13
@@ -377,7 +377,7 @@ BarWidget {
       spacing: 1
 
       Image {
-        source: root.iconSourceForProvider(chip.modelData)
+        source: root.iconSourceForProvider(chip.modelData, root.bar ? root.bar.background : Color.bar.background)
         width: 13
         height: 13
         sourceSize.width: 13
@@ -908,7 +908,7 @@ BarWidget {
     spacing: 8
 
     Image {
-      source: root.iconSourceForProvider(provider)
+      source: root.iconSourceForProvider(provider, root.background)
       Layout.preferredWidth: 16
       Layout.preferredHeight: 16
       sourceSize.width: 16
diff --git a/test/shell.d/fixtures/bar-widget-contract/shell.qml b/test/shell.d/fixtures/bar-widget-contract/shell.qml
index 40955501..13c9f441 100644
--- a/test/shell.d/fixtures/bar-widget-contract/shell.qml
+++ b/test/shell.d/fixtures/bar-widget-contract/shell.qml
@@ -93,6 +93,12 @@ ShellRoot {
     if (typeof item.setting === "function") {
       root.assertEqual(item.setting("missing", "fallback"), "fallback", entry.id + " exposes setting fallback")
     }
+    if (entry.id === "omarchy.model-usage" && typeof item.iconSourceForProvider === "function") {
+      var darkIcon = String(item.iconSourceForProvider({ providerId: "codex" }, Qt.color("#1a1b26")))
+      var lightIcon = String(item.iconSourceForProvider({ providerId: "codex" }, Qt.color("#ffffff")))
+      root.assertTrue(darkIcon.indexOf("codex.svg") >= 0 && darkIcon.indexOf("codex-light.svg") < 0, entry.id + " uses the dark-theme Codex icon on dark surfaces")
+      root.assertTrue(lightIcon.indexOf("codex-light.svg") >= 0, entry.id + " uses the light-theme Codex icon on light surfaces")
+    }
 
     safeCall(item, "refresh", entry)
     safeCall(item, "close", entry)