Examine source code of One Piece ID

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#6e6e6e"
    }
  },
  "version": "2.0",
  "name": "One Piece ID",
  "manifest_version": 2,
  "description": "Just a simple theme for my lovely Mozilla..\n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/b7cd0e66e5e2a662952e304d4559155e8a68b1b21b44ca0528c87829451b9da0/https%3A//ponselgue.com\">Ayu Rozenda</a>"
}