Examine source code of Red Bricks wall

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Red Bricks wall",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(66, 66, 66, 0.5)",
      "toolbar_text": "rgb(234, 144, 50)",
      "frame": "rgb(129, 46, 23)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(190, 190, 190)",
      "popup": "rgb(235, 230, 223)",
      "popup_text": "rgb(132, 25, 0)",
      "tab_loading": "rgb(190, 190, 190)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{06e974a0-c468-45b9-9f91-3b623a7f3538}"
    }
  }
}