Examine source code of Confetti Theme

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "confetti@eduardh.com",
      "strict_min_version": "55.0"
    }
  },
  "name": "Confetti Theme",
  "version": "2019.10.19",
  "description": "Confetti is a Firefox theme which changes colors and adapts to the user's operating system color scheme.",
  "homepage_url": "https://github.com/eduardhojbota/confetti-theme",
  "permissions": [
    "theme",
    "alarms"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  }
}