Examine source code of Blue night forest

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Blue night forest",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(4, 10, 24)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(32, 32, 37)",
      "tab_background_text": "rgb(201, 232, 255)",
      "toolbar_field": "rgb(13, 34, 66)",
      "toolbar_field_text": "rgb(211, 239, 255)",
      "tab_line": "rgb(63, 98, 148)",
      "popup": "rgb(4, 10, 24)",
      "popup_text": "rgb(215, 226, 239)",
      "tab_loading": "rgb(63, 98, 148)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e5e953cb-dda7-4c77-8ee4-1e0f8ba43317}"
    }
  }
}