diff --git a/web/work_plane.js b/web/work_plane.js
index cda9f4e..259a901 100644
--- a/web/work_plane.js
+++ b/web/work_plane.js
@@ -33,10 +33,8 @@ function updateButtonStates() {
 }
 
 function rgbUrl() {
-  // Nuwa is reachable on host network on port 8877; the GUI is same-origin to
-  // presa-mano (8890). Use the upstream host directly.
-  const host = window.location.hostname;
-  return `http://${host}:8877/api/rgb?t=${Date.now()}`;
+  // Same-origin RGB proxy exposed by presa-mano (no CORS issues).
+  return `/api/calibration/rgb.jpg?t=${Date.now()}`;
 }
 
 function startRgbLoop() {