Update javascript/app.js

javascript/app.js

@@ -191,7 +191,7 @@ class MidiVisualizer extends HTMLElement{
     const [r, g, b] = colors[index];
 
     // Return the RGB color in the format "rgb(r, g, b)"
-    return {r: ${r}, g: ${g}, b: ${b}};
+    return { r, g, b };
 
     }