Examine source code of OldSchool

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "OldSchool",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(232, 220, 202)",
      "toolbar_text": "rgb(1, 0, 4)",
      "frame": "rgb(1, 0, 129)",
      "tab_background_text": "rgb(253, 255, 255)",
      "toolbar_field": "rgb(195, 195, 195)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(255, 229, 2)",
      "popup": "rgb(195, 195, 195)",
      "popup_text": "rgb(1, 0, 4)",
      "button_background_hover": "rgb(255, 0, 129)",
      "ntp_background": "rgb(1, 0, 4)",
      "sidebar": "rgb(195, 195, 195)",
      "tab_selected": "rgb(255, 0, 129)",
      "tab_text": "rgb(255, 229, 2)",
      "toolbar_bottom_separator": "rgb(1, 0, 4)",
      "toolbar_field_border": "rgb(1, 0, 4)",
      "toolbar_field_highlight_text": "rgb(255, 0, 129)",
      "toolbar_top_separator": "rgb(1, 0, 4)",
      "tab_loading": "rgb(255, 229, 2)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{24892524-1413-4c6e-9a12-6e1479adadef}"
    }
  }
}