Examine source code of Forest worms

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Forest worms",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(254, 239, 222, 0.5)",
      "toolbar_text": "rgb(123, 64, 0)",
      "frame": "rgb(254, 239, 222)",
      "tab_background_text": "rgb(191, 98, 0)",
      "toolbar_field": "rgb(248, 255, 229)",
      "toolbar_field_text": "rgb(36, 121, 68)",
      "tab_line": "rgb(136, 111, 0)",
      "popup": "rgb(255, 254, 230)",
      "popup_text": "rgb(0, 125, 119)",
      "ntp_background": "rgb(255, 254, 230)",
      "ntp_text": "rgb(123, 64, 0)",
      "tab_loading": "rgb(136, 111, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{13a11cad-f9e8-4ea7-9393-0b46051052ce}"
    }
  }
}