Examine source code of Tomorrow Night

{
  "name": "Tomorrow Night",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "7c6c4b3e-0682-4a6b-8f19-aef5e661e0ce.png"
    },
    "colors": {
      "frame": "rgba(29, 31, 33, 1)",
      "tab_background_text": "rgba(196, 200, 197, 1)",
      "toolbar": "rgba(29, 31, 33, 1)",
      "bookmark_text": "rgba(196, 200, 197, 1)",
      "toolbar_field": "rgba(44, 48, 51, 1)",
      "toolbar_field_text": "rgba(196, 200, 197, 1)"
    }
  }
}