Examine source code of Gray Tile

{
  "theme": {
    "images": {
      "theme_frame": "testheader.jpg"
    },
    "colors": {
      "frame": "#d9d9d9",
      "tab_background_text": "#262626"
    }
  },
  "version": "2.0",
  "name": "Gray Tile",
  "manifest_version": 2,
  "description": "Gray tile"
}