Examine source code of Dark Start

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Start",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(28, 28, 28)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(28, 28, 28)",
      "tab_background_text": "rgb(242, 242, 242)",
      "toolbar_field": "rgb(32, 32, 32)",
      "toolbar_field_text": "rgb(150, 150, 150)",
      "tab_line": "rgba(255, 255, 255, 0)",
      "popup": "rgb(36, 36, 36)",
      "popup_text": "rgb(242, 242, 242)",
      "button_background_active": "rgb(47, 47, 47)",
      "button_background_hover": "rgb(41, 41, 41)",
      "ntp_background": "rgb(28, 28, 28)",
      "ntp_text": "rgb(242, 242, 242)",
      "popup_border": "rgb(73, 73, 73)",
      "sidebar_border": "rgb(73, 73, 73)",
      "sidebar_text": "rgb(242, 242, 242)",
      "sidebar": "rgb(36, 36, 36)",
      "tab_loading": "rgb(211, 228, 255)",
      "tab_selected": "rgb(41, 41, 41)",
      "tab_text": "rgb(255, 255, 255)",
      "toolbar_bottom_separator": "rgb(64, 64, 64)",
      "toolbar_field_border_focus": "rgb(211, 228, 255)",
      "toolbar_field_border": "rgb(51, 51, 51)",
      "toolbar_top_separator": "rgb(28, 28, 28)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c43c2849-c9b5-4857-ae47-2bbc45810d3e}"
    }
  }
}