Examine source code of Fallout 4

{
  "name": "Fallout 4",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "cropped-1366-768-599133.jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(17, 212, 33, 1)",
      "toolbar": "rgba(255, 255, 255, 1)",
      "bookmark_text": "rgba(17, 212, 33, 1)",
      "toolbar_field": "rgba(28, 27, 27, 1)",
      "toolbar_field_text": "rgba(17, 212, 33, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  }
}