Examine source code of blackred squares

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "blackred squares",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgba(239, 239, 5, 0)",
      "toolbar_text": "rgb(217, 243, 4)",
      "frame": "rgb(243, 235, 238)",
      "tab_background_text": "rgb(252, 56, 2)",
      "toolbar_field": "rgba(224, 21, 21, 0)",
      "toolbar_field_text": "rgb(248, 242, 14)",
      "tab_line": "rgb(214, 240, 9)",
      "popup": "rgb(18, 16, 14)",
      "popup_text": "rgb(243, 237, 4)",
      "tab_loading": "rgb(214, 240, 9)"
    }
  }
}