Examine source code of Icons by Doodle

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Icons by Doodle",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(225, 234, 239, 0.34)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(18, 30, 89)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(1, 35, 249)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_text": "rgb(1, 35, 249)",
      "tab_loading": "rgb(1, 35, 249)"
    }
  }
}