Examine source code of Material Dark

{
  "manifest_version": 2,
  "name": "Material Dark",
  "version": "2.0",
  "description": "Material Dark Theme for Firefox",
  "theme": {
    "colors": {
      "frame": "#202124",
      "frame_inactive": "#292A2D",
      "tab_text": "#F1F3F4",
      "tab_background_text": "#9AA0A6",
      "tab_background_separator": "#3C4043",
      "tab_selected": "#292A2D",
      "tab_line": "#8AB4F8",
      "tab_loading": "#8AB4F8",
      "icons": "#E8EAED",
      "icons_attention": "#8AB4F8",
      "toolbar": "#292A2D",
      "toolbar_top_separator": "#202124",
      "toolbar_bottom_separator": "#202124",
      "toolbar_vertical_separator": "#3C4043",
      "toolbar_field": "#202124",
      "toolbar_field_focus": "#202124",
      "toolbar_field_text": "#E8EAED",
      "toolbar_field_border": "#202124",
      "toolbar_field_border_focus": "#8AB4F8",
      "toolbar_field_separator": "#3C4043",
      "toolbar_field_highlight": "#384961",
      "toolbar_field_highlight_text": "#FFFFFF",
      "popup": "#292A2D",
      "popup_text": "#E8EAED",
      "popup_border": "#3C4043",
      "popup_highlight": "#3C4043",
      "popup_highlight_text": "#FFFFFF",
      "button_background_hover": "#3C4043",
      "button_background_active": "#4F5357",
      "bookmark_text": "#E8EAED",
      "sidebar": "#202124",
      "sidebar_border": "#3C4043",
      "sidebar_highlight": "#384961",
      "sidebar_text": "#E8EAED",
      "sidebar_highlight_text": "#FFFFFF",
      "ntp_text": "#E8EAED",
      "ntp_background": "#202124"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "material-dark@pro-bandey.com"
    }
  }
}