Examine source code of Darky

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Darky",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(34, 34, 34)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(217, 217, 217)",
      "toolbar_field": "rgb(47, 47, 47)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(97, 0, 255)",
      "popup": "rgb(40, 40, 40)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(97, 0, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{be874b5e-3059-43c7-9318-1e7f58a7fdc5}"
    }
  }
}