color = enum {
	red;
	orange;
	yellow;
	green;
	blue;
	# "It is customary to list indigo as a color lying between blue and violet, but it has
	# never seemed to me that indigo is worth the dignity of being considered a separate
	# color. To my eyes it seems merely deep blue." --Isaac Asimov
	indigo;
	violet;
}

opt_color_record = record {
	my_color: optional<color>;
}
