Examine source code of Hands Heart

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Hand Heart",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 196, 138, 0.5)",
      "toolbar_text": "rgb(70, 25, 0)",
      "frame": "rgb(255, 184, 55)",
      "tab_background_text": "rgb(204, 57, 0)",
      "toolbar_field": "rgba(255, 244, 224, 0.75)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(255, 91, 0)",
      "popup": "rgb(255, 244, 224)",
      "popup_text": "rgb(70, 25, 0)",
      "tab_loading": "rgb(255, 91, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8f0baa3d-9c44-401f-81a3-8d1d26392ca4}"
    }
  }
}