Examine source code of Autumn

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Autumn",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 255, 255, 0)",
      "toolbar_text": "rgb(252, 252, 252)",
      "frame": "rgb(50, 50, 50)",
      "tab_background_text": "rgb(207, 207, 207)",
      "toolbar_field": "rgba(0, 79, 119, 0)",
      "toolbar_field_text": "rgb(252, 252, 252)",
      "tab_line": "rgba(241, 241, 241, 0)",
      "popup": "rgba(239, 239, 239, 0.9)",
      "popup_text": "rgb(40, 40, 40)",
      "icons_attention": "rgb(2, 159, 253)",
      "tab_loading": "rgba(241, 241, 241, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{db6466c4-b04b-42fc-b94e-7de7c4b221fb}"
    }
  }
}