Examine source code of transparent only

{
  "theme": {
    "images": {
      "theme_frame": "bg.png"
    },
    "colors": {
      "frame": "#171414",
      "tab_background_text": "#f2f0ef"
    }
  },
  "version": "2.0",
  "name": "transparent only",
  "manifest_version": 2,
  "description": "just transparent"
}