Examine source code of Hackthebox UI

{
  "name": "Hackthebox UI",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "htb-theme-blank.png"
    },
    "colors": {
      "frame": "rgba(20, 29, 43, 1)",
      "tab_background_text": "rgba(164, 177, 205, 1)",
      "toolbar": "rgba(26, 35, 50, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(20, 29, 43, 1)",
      "toolbar_field_text": "rgba(164, 177, 205, 1)",
      "tab_line": "rgba(26, 35, 50, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d9ded1a1-1e88-47c6-abcc-ed304346be4a}"
    }
  }
}