Examine source code of Night Shapes

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Night Shapes",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-030-0f935cfde055600d01a959c5c15353de.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(27, 40, 45)",
      "toolbar_text": "rgb(141, 225, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(202, 239, 255)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(0, 210, 255)",
      "popup": "rgb(27, 40, 45)",
      "popup_text": "rgb(141, 225, 255)",
      "tab_loading": "rgb(0, 210, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d19d911c-5bd4-4c01-ab91-36eb97471a71}"
    }
  }
}