static Color clientPropertyColor( JComponent c, String key, Color defaultValue ) {
		return clientProperty( c, key, defaultValue, Color.class );
	}
Checks whether a client property of a component is a color and returns its value.
If the client property is not set, or not a color, defaultValue is returned.
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatClientProperties.java