Examine source code of Gruvbox dark stuff

{
  "name": "Gruvbox dark stuff",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "empty.png"
    },
    "colors": {
      "frame": "rgba(40, 40, 40, 1)",
      "tab_background_text": "rgba(131, 165, 152, 1)",
      "toolbar": "rgba(40, 40, 40, 1)",
      "bookmark_text": "rgba(131, 165, 152, 1)",
      "toolbar_field": "rgba(102, 92, 84, 1)",
      "toolbar_field_text": "rgba(131, 165, 152, 1)"
    }
  }
}