diff --git a/dashboard/js/ambient_renderer.js b/dashboard/js/ambient_renderer.js
index a25aec2..5a84b89 100644
--- a/dashboard/js/ambient_renderer.js
+++ b/dashboard/js/ambient_renderer.js
@@ -766,6 +766,11 @@
     }
 
     function getPersonColor(personName) {
+        // Identity name fields (personName/person_label) are optional on the wire;
+        // never dereference an undefined name. Today's sole caller guards with
+        // `if (personName)`, but harden the helper so the contract holds for any
+        // future caller (audit bf-gcotl / parent bf-2gmx).
+        if (!personName) return '#6b7280'; // Grey for unknown (matches line ~629)
         // Generate consistent color from name
         let hash = 0;
         for (let i = 0; i < personName.length; i++) {
diff --git a/dashboard/js/ble-panel.js b/dashboard/js/ble-panel.js
index 548002e..ff01ea1 100644
--- a/dashboard/js/ble-panel.js
+++ b/dashboard/js/ble-panel.js
@@ -825,6 +825,11 @@
     }
 
     function getColorForPerson(personName) {
+        // Identity name fields (person_name/personName) are optional on the wire;
+        // never dereference an undefined name. Currently has no callers, but
+        // harden the helper so it is safe for any future caller
+        // (audit bf-gcotl / parent bf-2gmx).
+        if (!personName) return '#888888'; // device default color (matches line ~181)
         // Check if we have a person with this name in our people list
         var person = state.people.find(function(p) { return p.name === personName; });
         if (person && person.color) {