Examine source code of Cool Dark

{
  "theme": {
    "images": {
      "theme_frame": "firefox.png"
    },
    "colors": {
      "frame": "#9c9c9c",
      "tab_background_text": "#5272ff"
    }
  },
  "version": "2.0",
  "name": "Cool Dark",
  "manifest_version": 2,
  "description": "Cool dark blue and black persona with faded tab effect!"
}