Examine source code of High End Blue

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Night Machine",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-036-40a272fe657f748396e017c7a64ee2dc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(31, 34, 61)",
      "toolbar_text": "rgb(247, 250, 255)",
      "frame": "rgb(29, 37, 74)",
      "tab_background_text": "rgb(247, 250, 255)",
      "toolbar_field": "rgb(31, 34, 61)",
      "toolbar_field_text": "rgb(247, 250, 255)",
      "tab_line": "rgb(183, 12, 12)",
      "popup": "rgb(31, 34, 61)",
      "popup_text": "rgb(247, 250, 255)",
      "button_background_active": "rgb(27, 31, 150)",
      "button_background_hover": "rgb(26, 106, 106)",
      "icons": "rgb(48, 213, 210)",
      "ntp_background": "rgb(20, 33, 85)",
      "tab_loading": "rgb(183, 12, 12)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{96f60937-5f6f-4d3a-bbaa-fb2462b9c565}"
    }
  }
}