Examine source code of Edge Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Edge Dark",
  "description": "An Edge theme with a dark color scheme.",
  "author": "ArrJay",
  "theme": {
    "properties": {
      "content_color_scheme": "dark"
    },
    "colors": {
      "bookmark_text": "#FFFFFF",
      "button_background_active": "#555555",
      "button_background_hover": "#4A4A4A",
      "icons": "#FFFFFF",
      "icons_attention": "#81B9EA",
      "frame": "#202020",
      "frame_inactive": "#2E2E2E",
      "ntp_background": "#333333",
      "ntp_text": "#FFFFFF",
      "popup": "#4A4A4A",
      "popup_border": "#4A4A4A",
      "popup_highlight": "#575757",
      "popup_highlight_text": "#FFFFFF",
      "popup_text": "#FFFFFF",
      "sidebar": "#333333",
      "sidebar_border": "#686868",
      "sidebar_highlight": "#454545",
      "sidebar_highlight_text": "#FFFFFF",
      "sidebar_text": "#FFFFFF",
      "tab_background_text": "#FFFFFF",
      "tab_line": "#3B3B3B",
      "tab_loading": "#67ACE5",
      "tab_selected": "#3B3B3B",
      "tab_text": "#FFFFFF",
      "toolbar": "#3B3B3B",
      "toolbar_bottom_separator": "#686868",
      "toolbar_field": "#2B2B2B",
      "toolbar_field_border": "#3B3B3B",
      "toolbar_field_border_focus": "#6EAEE7",
      "toolbar_field_focus": "#2B2B2B",
      "toolbar_field_highlight": "#98B8E9",
      "toolbar_field_highlight_text": "#000000",
      "toolbar_field_text": "#FFFFFF",
      "toolbar_field_text_focus": "#FFFFFF",
      "toolbar_text": "#FFFFFF",
      "toolbar_top_separator": "#1B1B1B",
      "toolbar_vertical_separator": "#6A6A6A"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e4b4999f-6eef-446f-b1cb-30bb78e99a78}"
    }
  }
}