Examine source code of Firework explode

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Firework explode",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(34, 34, 37, 0.75)",
      "toolbar_text": "rgb(255, 215, 135)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(255, 79, 0)",
      "toolbar_field": "rgb(253, 255, 225)",
      "toolbar_field_text": "rgb(54, 0, 146)",
      "tab_line": "rgb(255, 123, 228)",
      "popup": "rgb(19, 19, 40)",
      "popup_text": "rgb(0, 255, 128)",
      "tab_loading": "rgb(255, 123, 228)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6c09cebc-48f7-42a9-b710-f00171216467}"
    }
  }
}