diff --git a/frontend/js/map.js b/frontend/js/map.js
index 8db604e..6b93531 100644
--- a/frontend/js/map.js
+++ b/frontend/js/map.js
@@ -352,8 +352,12 @@ function _tmX(ctx, cx, cy, r, col) {
 }
 
 // ── True-3D colour helpers ────────────────────────────────────────────────
-function _h2r(hex) {               // hex → [r,g,b]
-  hex = hex.replace('#','');
+function _h2r(hex) {               // hex or rgb() → [r,g,b]
+  if (typeof hex === 'string' && hex.startsWith('rgb')) {
+    const m = hex.match(/\d+/g);
+    return m ? [+m[0], +m[1], +m[2]] : [0, 0, 0];
+  }
+  hex = (hex || '').replace('#','');
   if (hex.length === 3) hex = hex[0]+hex[0]+hex[1]+hex[1]+hex[2]+hex[2];
   return [parseInt(hex.slice(0,2),16), parseInt(hex.slice(2,4),16), parseInt(hex.slice(4,6),16)];
 }