The Diamond

[meeta gaur]

interface Pair<K,V>
{
	K getKey();
	V getValue();
}
class Colour<T>{}
class OrderedPair<K,V> implements Pair<K,V> 
{
	private K k;
	private V v;

	OrderedPair(K k,V v){
		this.k=k;
		this.v=v;
	}
	public K getKey(){
		return k;
	}
	public V getValue(){
		return v;
	}
	public static void main(String[] args) 
	{
		Pair<String,Integer> obj1=new OrderedPair<>("k1",13);
		System.out.println(obj1.getKey()+" = "+obj1.getValue());

		Pair<String,String> obj2=new OrderedPair<>("k2","hello");
		System.out.println(obj2.getKey()+" = "+obj2.getValue());

		Pair<String,Colour<String>> obj3=new OrderedPair<>("k3",new Colour<>());
	}
}

OrderedPair.java:32: error: incompatible types
Pair<String,Colour<String>> obj3=new OrderedPair<>("k3",new Colour<>());
^
required: Pair<String,Colour<String>>
found: OrderedPair<String,Colour<Object>>
1 error

Why diamond isn't working for Colour?