Examine source code of Slack Discotheque

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Slack Discotheque",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-037-b73f9b34467ba541de861f5b4c0c6316.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(32, 32, 32)",
      "toolbar_text": "rgb(250, 225, 195)",
      "frame": "rgb(106, 27, 27)",
      "tab_background_text": "rgb(210, 164, 84)",
      "toolbar_field": "rgba(106, 27, 27, 0)",
      "toolbar_field_text": "rgb(210, 164, 84)",
      "tab_line": "rgb(210, 164, 84)",
      "popup": "rgb(26, 29, 33)",
      "popup_text": "rgb(210, 164, 84)",
      "tab_loading": "rgb(210, 164, 84)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5e2fdf27-c118-47b0-93da-10e673ac23dd}"
    }
  }
}