（スクリプト）

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CursorPos : MonoBehaviour
{
    private Vector3 pos;
    public GameObject box;

    void Update()
    {
        pos = Input.mousePosition;

        if(pos.y > 500)
        {
            box.GetComponent<MeshRenderer>().material.color = Color.red;
        }
        else
        {
            box.GetComponent<MeshRenderer>().material.color = Color.green;
        }

        print(pos);
    }
}

（実行結果）