externalize pixel stuff, add pixel instance to plugin, remove old code

data/www/gradients.json

@@ -3,6 +3,10 @@
         "text": "None",
         "value": ["#000000", "#000000"]
     },
+    {
+        "text": "Stadler",
+        "value": ["#0B3F75", "#0B3F75"]
+    },
     {
         "text": "Blu",
         "value": ["#00416A", "#E4E5E6"]