Examine source code of Simple-Canvas

{
  "theme": {
    "images": {
      "theme_frame": "head.jpg"
    },
    "colors": {
      "frame": "#292929",
      "tab_background_text": "#292929"
    }
  },
  "version": "2.0",
  "name": "Simple-Canvas",
  "manifest_version": 2,
  "description": "Simple　Canvas"
}