Canvas Themeinator

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Canvas Themeinator",
  "version": "1.5.1",
  "description": "Gives Canvas more themes",
  "content_scripts": [
    {
      "matches": [
        "https://*.instructure.com/*"
      ],
      "css": [
        "style.css"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "storage"
  ],
  "action": {
    "default_title": "Choose Theme",
    "default_popup": "html/index.html"
  },
  "icons": {
    "32": "icon.png"
  }
}