Examine source code of FrameWhite

{
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "FrameWhite@Sungho.Hwang",
      "strict_min_version": "88.0"
    }
  },
  "name": "FrameWhite",
  "version": "141.1",
  "description": "Enjoy FrameWhite, FrameBlack and LightBlue, LightGreen, LightYellow, LightRed and BlueWhite, VioletWhite, GreenWhite, CyanWhite, RedWhite, OrangeWhite, KhakiWhite and Additional BlueGray, GreenGray, RedGray themes.",
  "icons": {
    "16": "icons/fw16.png",
    "32": "icons/fw30.png",
    "64": "icons/fw64.png"
  },
  "browser_action": {
    "default_icon": "icons/fw16.png",
    "default_title": "FrameWhite",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "theme"
  ]
}