public override void Validate( string value )
{
base.Validate( value );
string parsedValue = Color.Parse( value );
if ( parsedValue == null ) {
throw new FormatException( "Value cannot be parsed as a color." );
} else if ( parsedValue.Length == 0 && NotBlank ) {
throw new FormatException( "Value may not represent absence of color." );
}
}