Examine source code of Custom Highlight Color

{
  "manifest_version": 2,
  "name": "Custom Highlight Color",
  "version": "1.0",
  "description": "Easily customize the color of selected text. Features include saving highlights, copying all selections, and email integration. Perfect for research.",
  "author": "Implied Intellect <impliedintellect@gmail.com>",
  "homepage_url": "https://impliedintellect.com",
  "browser_specific_settings": {
    "gecko": {
      "id": "highlight-color-changer@impliedintellect.com",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "clipboardWrite",
    "contextMenus",
    "downloads"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Highlight Color Changer",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/highlight-48.png",
      "96": "icons/highlight-96.png",
      "128": "icons/highlight-128.png"
    }
  },
  "icons": {
    "48": "icons/highlight-48.png",
    "96": "icons/highlight-96.png",
    "128": "icons/highlight-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}