diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
index 23ab722..078b778 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
@@ -631,20 +631,30 @@ function setTheme(theme) {
     themeToggleBtn.title = next === "dark" ? "Switch to light mode" : "Switch to dark mode";
   }
   // Invalidate cached bookmark chip colours so they pick up the new theme palette.
+  // Guard: bmRevision (var in bookmarks.js) may not exist during the initial
+  // setTheme() call at load time (bookmarks.js loads after app.js).
   if (typeof bmRevision !== "undefined") {
     bmRevision++;
-    // Re-apply colours to existing bookmark chips using the new palette.
-    try {
-      const colorMap = bmCategoryColorMap();
-      const ref = typeof bmList !== "undefined" ? bmList : [];
-      document.querySelectorAll(".spectrum-bookmark-chip").forEach((chip) => {
-        const bm = ref.find((b) => b.id === chip.dataset.bmId);
-        if (!bm) return;
-        const col = colorMap[bm.category || ""] || BOOKMARK_MARKER_FALLBACK;
-        chip.style.setProperty("--bm-cat-bg", col);
-        chip.style.setProperty("--bm-cat-fg", bmContrastFg(col));
-      });
-    } catch (_) {}
+    // Force the browser to recalculate styles after the data-theme attribute
+    // change so that getComputedStyle returns the new CSS variable values.
+    void getComputedStyle(document.documentElement).getPropertyValue("--bg");
+    const colorMap = bmCategoryColorMap();
+    const ref = typeof bmList !== "undefined" ? bmList : [];
+    const fallback = "#66d9ef";
+    document.querySelectorAll(".spectrum-bookmark-chip").forEach((chip) => {
+      const bm = ref.find((b) => b.id === chip.dataset.bmId);
+      if (!bm) return;
+      const col = colorMap[bm.category || ""] || fallback;
+      chip.style.setProperty("--bm-cat-bg", col);
+      chip.style.setProperty("--bm-cat-fg", bmContrastFg(col));
+    });
+    // Also clear cached DOM keys so the next spectrum draw rebuilds chips fresh.
+    const axisEl = document.getElementById("spectrum-bookmark-axis");
+    const leftEl = document.getElementById("spectrum-bookmark-side-left");
+    const rightEl = document.getElementById("spectrum-bookmark-side-right");
+    if (axisEl) axisEl.dataset.bmKey = "";
+    if (leftEl) leftEl.dataset.bmKey = "";
+    if (rightEl) rightEl.dataset.bmKey = "";
   }
   try { if (typeof scheduleSpectrumDraw === "function") scheduleSpectrumDraw(); } catch (_) {}
 }