Examine source code of Heilung Smoke

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Heilung Smoke",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(35, 48, 35, 0)",
      "toolbar_text": "rgb(155, 144, 132)",
      "frame": "rgb(41, 23, 4)",
      "tab_background_text": "rgb(116, 95, 66)",
      "toolbar_field": "rgb(193, 189, 185)",
      "toolbar_field_text": "rgb(93, 61, 33)",
      "tab_line": "rgba(155, 97, 48, 0.73)",
      "popup": "rgb(39, 55, 39)",
      "popup_text": "rgb(170, 167, 127)",
      "button_background_active": "rgb(113, 110, 71)",
      "ntp_text": "rgb(137, 146, 77)",
      "tab_loading": "rgba(155, 97, 48, 0.73)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{77a6c98c-b032-44d1-875d-f0f967797b16}"
    }
  }
}