Examine source code of Hatsune Miku: Car

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "Hatsune Miku Muscle Car",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(50, 50, 52, 0.4)",
      "toolbar_text": "rgb(190, 190, 190)",
      "frame": "rgb(50, 50, 52)",
      "tab_background_text": "rgb(233, 233, 233)",
      "toolbar_field": "rgba(134, 206, 203, 0.7)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(134, 206, 203)",
      "popup": "rgb(74, 74, 79)",
      "popup_text": "rgb(233, 233, 233)",
      "tab_loading": "rgb(134, 206, 203)"
    }
  }
}