Examine source code of Doodle Beta

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#858585",
      "tab_background_text": "#8f8f8f"
    }
  },
  "version": "2.0",
  "name": "Doodle Beta",
  "manifest_version": 2,
  "description": "Trying to recreate all those doodles I made back in Elementary school, unfinished. May never be, afterall, it is made for my own personal use."
}