Examine source code of Blurple depth FS

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Blurple depth FS",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top",
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat",
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgb(231, 234, 250)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(191, 198, 241)",
      "tab_background_text": "rgb(29, 29, 29)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(231, 234, 250)",
      "popup": "rgb(41, 42, 45)",
      "popup_text": "rgb(255, 255, 255)",
      "ntp_background": "rgb(41, 42, 45)",
      "popup_border": "rgb(56, 57, 60)",
      "popup_highlight": "rgb(149, 160, 233)",
      "toolbar_bottom_separator": "rgb(231, 234, 250)",
      "toolbar_field_border_focus": "rgb(149, 160, 233)",
      "toolbar_field_highlight": "rgb(149, 160, 233)",
      "toolbar_top_separator": "rgb(231, 234, 250)",
      "toolbar_vertical_separator": "rgb(231, 234, 250)",
      "tab_loading": "rgb(231, 234, 250)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{369538ee-febb-4f8e-9287-5fb0728145da}"
    }
  }
}