Examine source code of Dandelion Clock

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dandelion Clock",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 255, 255, 0.33)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(103, 198, 198)",
      "tab_background_text": "rgb(92, 94, 94)",
      "toolbar_field": "rgba(225, 229, 233, 0.71)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(101, 151, 131)",
      "popup": "rgb(218, 224, 228)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(101, 151, 131)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e4ca784a-6038-4c0f-9d35-bae7d76e304b}"
    }
  }
}