Examine source code of Dark Rock

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Rock",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgb(15, 45, 61)",
      "toolbar_text": "rgb(28, 183, 183)",
      "frame": "rgb(142, 179, 201)",
      "tab_background_text": "rgb(100, 233, 233)",
      "toolbar_field": "rgb(119, 231, 203)",
      "toolbar_field_text": "rgb(9, 0, 2)",
      "tab_line": "rgb(122, 206, 218)",
      "popup": "rgb(115, 198, 198)",
      "popup_text": "rgb(15, 21, 141)",
      "tab_loading": "rgb(122, 206, 218)"
    }
  }
}