Examine source code of Gruvbox Theme

{
  "manifest_version": 2,
  "version": "3.0",
  "name": "Gruvbox Theme v1.1",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(60, 56, 54)",
      "toolbar_text": "rgb(235, 219, 178)",
      "frame": "rgb(40, 40, 40)",
      "tab_background_text": "rgb(235, 219, 178)",
      "toolbar_field": "rgb(40, 40, 40)",
      "toolbar_field_text": "rgb(235, 219, 178)",
      "tab_line": "rgba(235, 219, 178, 0)",
      "popup": "rgb(60, 56, 54)",
      "popup_text": "rgb(235, 219, 178)",
      "button_background_active": "rgb(127, 111, 100)",
      "button_background_hover": "rgb(168, 153, 132)",
      "frame_inactive": "rgb(29, 32, 33)",
      "icons_attention": "rgba(254, 128, 25, 0.5)",
      "icons": "rgb(235, 219, 178)",
      "ntp_background": "rgb(40, 40, 40)",
      "ntp_text": "rgb(235, 219, 178)",
      "popup_border": "rgb(60, 56, 54)",
      "popup_highlight_text": "rgb(235, 219, 178)",
      "popup_highlight": "rgba(168, 153, 132, 0.5)",
      "sidebar_border": "rgb(60, 56, 54)",
      "sidebar_highlight_text": "rgb(184, 187, 38)",
      "sidebar_highlight": "rgb(60, 56, 54)",
      "sidebar_text": "rgb(235, 219, 178)",
      "sidebar": "rgb(60, 56, 54)",
      "tab_background_separator": "rgb(60, 56, 54)",
      "tab_loading": "rgba(168, 153, 132, 0.5)",
      "tab_selected": "rgb(60, 56, 54)",
      "tab_text": "rgb(235, 219, 178)",
      "toolbar_bottom_separator": "rgb(60, 56, 54)",
      "toolbar_field_border_focus": "rgba(235, 219, 178, 0.45)",
      "toolbar_field_border": "rgb(40, 40, 40)",
      "toolbar_field_focus": "rgb(40, 40, 40)",
      "toolbar_field_highlight_text": "rgb(235, 219, 178)",
      "toolbar_field_highlight": "rgb(127, 111, 100)",
      "toolbar_field_separator": "rgb(184, 187, 38)",
      "toolbar_field_text_focus": "rgb(235, 219, 178)",
      "toolbar_top_separator": "rgb(40, 40, 40)",
      "toolbar_vertical_separator": "rgb(60, 56, 54)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{aa92c77d-98a5-4fdd-923b-33dddff7623a}"
    }
  }
}