Examine source code of Scroll Tester New Tab

{
  "name": "skyscraper SpiderMan HD Theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "wallpaperflare.com_wallpaper (2).jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(156, 61, 161, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(103, 34, 214, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{613ea511-97d0-405d-b615-daba5b1d3e89}"
    }
  }
}