Examine source code of Planet too hot

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Hot planet",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(70, 25, 10, 0.75)",
      "toolbar_text": "rgb(255, 245, 204)",
      "frame": "rgb(204, 123, 31)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(211, 211, 211)",
      "toolbar_field_text": "rgb(7, 6, 49)",
      "tab_line": "rgb(205, 134, 255)",
      "popup": "rgb(213, 226, 229)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(205, 134, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bccc22d7-884d-4450-8176-99025fcec135}"
    }
  }
}