Examine source code of gruvbox dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "gruvbox",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(60, 56, 54)",
      "toolbar_text": "rgb(184, 187, 38)",
      "frame": "rgb(40, 40, 40)",
      "tab_background_text": "rgb(211, 134, 155)",
      "toolbar_field": "rgb(184, 187, 38)",
      "toolbar_field_text": "rgb(40, 40, 40)",
      "tab_line": "rgb(250, 219, 47)",
      "popup": "rgb(60, 56, 54)",
      "popup_text": "rgb(184, 187, 38)",
      "icons_attention": "rgb(214, 93, 14)",
      "ntp_background": "rgb(40, 40, 40)",
      "ntp_text": "rgb(250, 219, 47)",
      "popup_highlight_text": "rgb(251, 241, 199)",
      "popup_highlight": "rgb(69, 133, 136)",
      "sidebar_text": "rgb(184, 187, 38)",
      "tab_loading": "rgb(254, 128, 25)",
      "tab_text": "rgb(250, 219, 47)",
      "toolbar_field_highlight_text": "rgb(251, 241, 199)",
      "toolbar_field_highlight": "rgb(69, 133, 136)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4a079f3b-d83c-4367-923f-abb80e97126b}"
    }
  }
}