Examine source code of WWDC 2019

{
  "name": "WWDC 2019",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "wwdc-2019 copy.jpeg"
    },
    "colors": {
      "frame": "rgba(15, 20, 36, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(0, 0, 0, 0.01)",
      "bookmark_text": "rgba(252, 252, 252, 0.8)",
      "toolbar_field": "rgba(0, 0, 0, 0)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)"
    }
  }
}