Examine source code of Fog on the river

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Fog on the river",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(22, 72, 75, 0)",
      "toolbar_text": "rgb(249, 249, 249)",
      "frame": "rgb(0, 2, 3)",
      "tab_background_text": "rgb(148, 157, 173)",
      "toolbar_field": "rgba(0, 0, 0, 0)",
      "toolbar_field_text": "rgb(252, 252, 252)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(243, 248, 249)",
      "popup_text": "rgb(0, 2, 3)",
      "tab_loading": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{961b9be9-4e05-4edc-8547-028f3183da9e}"
    }
  }
}