Examine source code of simple gray

{
  "theme": {
    "images": {
      "theme_frame": "persona.jpg"
    },
    "colors": {
      "frame": "#9e9e9e",
      "tab_background_text": "#333333"
    }
  },
  "version": "2.0",
  "name": "simple gray",
  "manifest_version": 2,
  "description": "Just a simple gray gradient."
}