Examine source code of cityweirdcore

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "city",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(37, 0, 59)",
      "toolbar_text": "rgb(240, 214, 255)",
      "frame": "rgb(11, 0, 19)",
      "tab_background_text": "rgb(240, 214, 255)",
      "toolbar_field": "rgb(37, 0, 59)",
      "toolbar_field_text": "rgb(240, 214, 255)",
      "tab_line": "rgb(96, 0, 153)",
      "popup": "rgb(96, 0, 153)",
      "popup_text": "rgb(240, 214, 255)",
      "tab_loading": "rgb(96, 0, 153)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d2398dc2-e253-4848-9946-8302aba6ee87}"
    }
  }
}