Examine source code of airplane2

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "airplane2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat-y"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 12, 16, 0.33)",
      "toolbar_text": "rgb(252, 255, 0)",
      "frame": "rgb(228, 73, 14)",
      "tab_background_text": "rgb(252, 255, 0)",
      "toolbar_field": "rgba(111, 20, 173, 0)",
      "toolbar_field_text": "rgb(252, 255, 0)",
      "tab_line": "rgb(252, 255, 0)",
      "popup": "rgb(226, 74, 16)",
      "popup_text": "rgb(252, 255, 0)",
      "tab_loading": "rgb(252, 255, 0)"
    }
  }
}