/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
 
	static class Car{
		private final String color;
		public String getColor(){return color;}
		public Car(String color){this.color = color;}
	}
 
 
	public static void main (String[] args) throws java.lang.Exception
	{
		List<String> definedOrder = Arrays.asList("green", "grey", "blue", "red");
		List<Car> cars = new ArrayList<>(Arrays.asList(
			new Car("red"), new Car("green"), new Car("blue")
			));
 
		Comparator<Car> carComparator = Comparator.comparing(
        c -> definedOrder.indexOf(c.getColor()));
        Collections.sort(cars, carComparator);
 
        cars.stream().map(Car::getColor).forEach(System.out::println);
 
	}
}

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