diff --git a/client/gui_client.py b/client/gui_client.py
index 90e1b7a..8e1ae4b 100644
--- a/client/gui_client.py
+++ b/client/gui_client.py
@@ -180,6 +180,23 @@ def _is_phys(v) -> bool:
     return isinstance(v, dict) and "value" in v and "unit" in v
 
 
+_CHANGED_BG = QColor("#1e3a00")
+
+
+def _flatten_values(data: dict, prefix: str = "") -> dict[str, object]:
+    """Flat dict of path → value for every physical leaf, using '/' separator."""
+    result = {}
+    for k, v in data.items():
+        if k == "ts":
+            continue
+        path = f"{prefix}/{k}" if prefix else k
+        if _is_phys(v):
+            result[path] = v.get("value")
+        elif isinstance(v, dict):
+            result.update(_flatten_values(v, path))
+    return result
+
+
 def _extract_phys(data: dict, prefix: str = "") -> dict[str, dict]:
     """Return a flat dict of path → {value, unit} for every physical leaf."""
     result = {}
@@ -302,10 +319,15 @@ class DashboardTab(QWidget):
         self._tree.setAlternatingRowColors(True)
         self._tree.setRootIsDecorated(True)
         layout.addWidget(self._tree)
+        self._prev_flat: dict = {}
 
     def update(self, snapshot: dict):
         self._ts.setText(f"Last update:  {snapshot.get('ts', '—')}")
 
+        curr_flat = _flatten_values(snapshot)
+        changed = {p for p, v in curr_flat.items() if v != self._prev_flat.get(p)}
+        self._prev_flat = curr_flat
+
         expanded = self._expanded_paths()
         self._tree.clear()
 
@@ -320,38 +342,51 @@ class DashboardTab(QWidget):
             d_item.setFont(0, bold)
             d_item.setForeground(0, domain_color)
             for obj_name, fields in domain_data.items():
+                path = f"{domain}/{obj_name}"
                 if _is_phys(fields):
                     item = QTreeWidgetItem([obj_name, str(fields["value"]), fields["unit"], fields.get("str_state", "")])
                     item.setTextAlignment(1, Qt.AlignRight | Qt.AlignVCenter)
+                    if path in changed:
+                        for col in range(4):
+                            item.setBackground(col, _CHANGED_BG)
                     d_item.addChild(item)
                 elif isinstance(fields, dict):
                     obj_item = QTreeWidgetItem([obj_name])
                     obj_item.setFont(0, bold)
-                    self._add_fields(obj_item, fields, f"{domain}/{obj_name}")
+                    self._add_fields(obj_item, fields, path, changed)
                     d_item.addChild(obj_item)
                 else:
                     item = QTreeWidgetItem([obj_name, str(fields), "", ""])
                     item.setTextAlignment(1, Qt.AlignRight | Qt.AlignVCenter)
+                    if path in changed:
+                        for col in range(4):
+                            item.setBackground(col, _CHANGED_BG)
                     d_item.addChild(item)
             self._tree.addTopLevelItem(d_item)
 
         self._tree.expandAll()
         self._restore_expanded(expanded)
 
-    def _add_fields(self, parent: QTreeWidgetItem, data: dict, path: str):
+    def _add_fields(self, parent: QTreeWidgetItem, data: dict, path: str, changed: set):
         for k, v in data.items():
             child_path = f"{path}/{k}"
             if _is_phys(v):
                 item = QTreeWidgetItem([k, str(v["value"]), v["unit"], v.get("str_state", "")])
                 item.setTextAlignment(1, Qt.AlignRight | Qt.AlignVCenter)
+                if child_path in changed:
+                    for col in range(4):
+                        item.setBackground(col, _CHANGED_BG)
                 parent.addChild(item)
             elif isinstance(v, dict):
                 node = QTreeWidgetItem([k])
-                self._add_fields(node, v, child_path)
+                self._add_fields(node, v, child_path, changed)
                 parent.addChild(node)
             else:
                 item = QTreeWidgetItem([k, str(v), "", ""])
                 item.setTextAlignment(1, Qt.AlignRight | Qt.AlignVCenter)
+                if child_path in changed:
+                    for col in range(4):
+                        item.setBackground(col, _CHANGED_BG)
                 parent.addChild(item)
 
     # ── preserve expand state across refreshes ──────────────────────────────