Examine source code of gruvbox-darker

{
  "theme": {
    "colors": {
      "frame": "#282828",
      "tab_background_text": "#a89984",
      "tab_selected": "#3c3836",
      "icons_attention": "#458588",
      "popup": "#504945",
      "popup_border": "#32302f",
      "popup_highlight": "#83a598",
      "popup_highlight_text": "#fbf1c7",
      "popup_text": "#a89884",
      "tab_line": "#a89984",
      "tab_loading": "#8ec07c",
      "tab_text": "#ebdbb2",
      "toolbar": "#3c3836",
      "toolbar_bottom_separator": "#1d2021",
      "toolbar_field": "#504945",
      "toolbar_field_focus": "#7c6f64",
      "toolbar_field_border": "#282828",
      "toolbar_field_border_focus": "#458588",
      "toolbar_field_text": "#d5c4a1",
      "toolbar_field_text_focus": "#fbf1c7",
      "ntp_background": "#282828",
      "ntp_text": "fbf1c7",
      "sidebar": "#3c3836",
      "sidebar_border": "#282828",
      "sidebar_highlight": "#bdae93",
      "sidebar_text": "#fbf1c7",
      "button_background_active": "#665c54",
      "button_background_hover": "#504945"
    }
  },
  "name": "gruvbox-dark",
  "author": "Hans Ole Hatzel",
  "homepage_url": "https://github.com/hatzel/gruvbox-dark-firefox",
  "manifest_version": 2,
  "version": "0.2resigned1",
  "description": "A theme based on the gruvbox-dark colors",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a7d76179-719f-4df1-942b-f849044bc197}"
    }
  }
}