Examine source code of Minimal Steam

{
  "manifest_version": 2,
  "name": "Minimal Steam",
  "version": "1.0",
  "description": "Simple Two Color Theme Inspired By SteamOS",
  "theme": {
    "colors": {
      "frame": "#171D25",
      "toolbar": "#171D25",
      "toolbar_field": "#171D25",
      "toolbar_field_border": "#171D25",
      "toolbar_vertical_separator": "#171D25",
      "toolbar_top_separator": "#171D25",
      "toolbar_bottom_separator": "#171D25",
      "tab_selected": "#171D25",
      "ntp_background": "#171D25",
      "popup": "#171D25",
      "popup_border": "#171D25",
      "sidebar": "#171D25",
      "sidebar_border": "#171D25",
      "ntp_text": "#FFFFFF",
      "popup_text": "#FFFFFF",
      "popup_highlight_text": "#FFFFFF",
      "sidebar_text": "#FFFFFF",
      "sidebar_highlight_text": "#FFFFFF",
      "bookmark_text": "#FFFFFF",
      "toolbar_field_text": "#A7B1BA",
      "tab_text": "#A7B1BA",
      "icons": "#A7B1BA",
      "button_background_active": "#262C34",
      "button_background_hover": "#262C34",
      "tab_line": "#262C34",
      "ntp_card_background": "#262C34",
      "popup_highlight": "#262C34",
      "sidebar_highlight": "#262C34",
      "icons_attention": "#262C34",
      "tab_background_text": "#A7B1BA"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f38e4e43-e2d9-44a2-a9d3-2eb20c47fcfd}"
    }
  }
}