Examine source code of ancient background

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "ancient background",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(72, 61, 40)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(29, 22, 15)",
      "tab_background_text": "rgb(221, 218, 214)",
      "toolbar_field": "rgb(214, 211, 204)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(245, 217, 186)",
      "popup": "rgb(208, 195, 179)",
      "popup_text": "rgb(33, 26, 19)",
      "toolbar_field_border_focus": "rgb(4, 2, 10)",
      "tab_loading": "rgb(245, 217, 186)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{91982feb-c602-4b62-8613-662a890eec32}"
    }
  }
}