Examine source code of EURO-2020

{
  "name": "EURO-2020",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "EURO-2020.jpg"
    },
    "colors": {
      "frame": "rgba(18, 17, 17, 0.62)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(252, 252, 252, 0.68)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(4, 186, 214, 0.68)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(0, 0, 0, 0.43)"
    }
  }
}