Examine source code of Black Glacier

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Black Glacier",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-009-f069b97f439938a011297c84464f0df6.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(145, 168, 185)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(166, 188, 207)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(193, 208, 221)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(145, 168, 185)",
      "popup": "rgb(137, 157, 176)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgb(151, 179, 200)",
      "button_background_hover": "rgb(145, 168, 185)",
      "ntp_background": "rgb(210, 222, 233)",
      "popup_border": "rgb(151, 179, 200)",
      "toolbar_field_border": "rgb(144, 165, 183)",
      "tab_loading": "rgb(145, 168, 185)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{184e43af-d255-4af5-ba0c-1fdc37117500}"
    }
  }
}