Examine source code of Thunder Rebirth!!

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Thunder!!",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg",
        "images/1.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center",
        "left center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(109, 100, 100)",
      "toolbar_text": "rgb(3, 3, 3)",
      "frame": "rgb(158, 146, 145)",
      "tab_background_text": "rgb(243, 239, 238)",
      "toolbar_field": "rgb(243, 239, 238)",
      "toolbar_field_text": "rgb(158, 128, 128)",
      "tab_line": "rgb(243, 10, 10)",
      "popup": "rgb(217, 210, 209)",
      "popup_text": "rgb(217, 45, 20)",
      "tab_loading": "rgb(243, 10, 10)"
    }
  }
}