Examine source code of Yet another blue

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Another blue",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 255, 255, 0)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgba(255, 255, 255, 0)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgba(255, 255, 255, 0.5)",
      "button_background_hover": "rgba(255, 255, 255, 0.25)",
      "icons": "rgb(255, 255, 255)",
      "tab_loading": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5216aee5-7024-4198-a88c-32850219709f}"
    }
  }
}