Examine source code of forest secret

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "the woods",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-023-f741aad3989b46322a7840a425068429.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(14, 97, 47)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(10, 62, 30)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(11, 77, 37)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(10, 54, 25)",
      "popup": "rgb(10, 62, 30)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(10, 54, 25)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9f70bd47-4997-4eda-8261-5d96869bea6a}"
    }
  }
}