Examine source code of Brecon Beacons Skyline

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "talybont forest",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 255, 255, 0.06)",
      "toolbar_text": "rgb(239, 245, 239)",
      "frame": "rgb(103, 198, 198)",
      "tab_background_text": "rgb(243, 239, 238)",
      "toolbar_field": "rgba(233, 229, 225, 0.52)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(191, 157, 116)",
      "popup": "rgba(228, 225, 218, 0.95)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(191, 157, 116)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{87af7e0b-ed78-40c8-92d4-2f0016950dd8}"
    }
  }
}