private void processIconFile(String path, InputStream is) throws IOException {
		int indexOf = path.indexOf("images/");
		if (indexOf < 0) {
			Msg.error(this, "Unknown file: " + path);
		}
		String relativePath = path.substring(indexOf, path.length());
		File dir = Application.getUserSettingsDirectory();
		File iconFile = new File(dir, relativePath);
		FileUtils.copyInputStreamToFile(is, iconFile);
	}
Assumes the file is a theme file and reads it.
Ghidra/Framework/Gui/src/main/java/generic/theme/ThemeReader.java