<xs:simpleType name="ColorPlusOpacity">
	<xs:annotation>
		<xs:documentation>List of three or four values (red, green, blue, opacity), separated by spaces. The values must be in the
			range between zero and one. If no opacity is given, it is assumed as 1.0.</xs:documentation>
	</xs:annotation>
	<xs:restriction base="core:doubleBetween0and1List">
		<xs:minLength value="3"/>
		<xs:maxLength value="4"/>
	</xs:restriction>
</xs:simpleType>