Examine source code of Space Travel (Red)

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Space Travel (Red)",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-026-829b05416f823e170310e7c826ad1bec.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(22, 20, 21)",
      "toolbar_text": "rgb(102, 38, 47)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(218, 67, 67)",
      "toolbar_field": "rgb(102, 38, 47)",
      "toolbar_field_text": "rgb(253, 59, 59)",
      "tab_line": "rgb(102, 38, 47)",
      "popup": "rgb(227, 95, 95)",
      "popup_text": "rgb(102, 38, 47)",
      "tab_selected": "rgb(227, 95, 95)",
      "tab_loading": "rgb(102, 38, 47)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4f04d8ef-94ab-4454-9237-b254665d08c1}"
    }
  }
}