Examine source code of dark surtr (arknights)

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "dark surtr (arknights)",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left bottom"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(9, 9, 9, 0)",
      "toolbar_text": "rgb(185, 160, 255)",
      "frame": "rgb(9, 9, 9)",
      "tab_background_text": "rgb(185, 160, 255)",
      "toolbar_field": "rgba(9, 9, 9, 0)",
      "toolbar_field_text": "rgb(185, 160, 255)",
      "tab_line": "rgb(185, 160, 255)",
      "popup": "rgb(185, 160, 255)",
      "popup_text": "rgb(240, 248, 255)",
      "ntp_background": "rgb(9, 9, 9)",
      "tab_loading": "rgb(185, 160, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b086e91-8e73-4c75-96c0-986448954d19}"
    }
  }
}