Dynamic linq and configuration file

I have two class :

public class Customer
{
    public string FirstName { get; set; }

    public string LastName { get; set; }

    public DateTime Date { get; set; }

    public bool isActif { get; set; }

    public Quantity Quantity { get; set; }
}

public class Quantity
{
    public string Color { get; set; }

    public int Number { get; set; }
}

And one instance for example :

Customer[] c = new Customer[]
{
    new Customer()
    {
        FirstName = "FirstName1",
        LastName = "LastName1",
        Date = DateTime.Now.Date,
        isActif = true,
        Quantity = new Quantity()
        {
            Number = 12,
            Color = "Blue"
        }
    },
    new Customer()
    {
        FirstName = "FirstName2",
        LastName = "LastName2",
        Date = DateTime.Now.Date.AddDays(2),
        isActif = false,
        Quantity = new Quantity()
        {
            Number = 13,
            Color = "Green"
        }
    }
};

I want to create a filter since a configuration file. For example I want to specify in a configuration file that i want to take only the customers with the property isActif = true. Or only the customer with Quantity.Color = "Green"

I think I'll do this with a LINQ Dynamic Query Library Link

I want advice about my configuration file structure and how to structure it in my code

Thank's