Model Binding with Checkboxes in MVC

I have a "Product Create" page and I need to add a Color porperty to it. One product might have more than one color, So I have written a seperate Color model and a ProductColorRelations model. With these models, I can bind many colors to a product.

public class ProductDetailViewModel
{
    public AY_PRODUCT product { get; set; }
    public List<AY_COLOR> colors { get; set; }
}


// ACTION ON LOAD
public ActionResult ProductsCreate()
{
    ProductDetailViewModel mdl = new ProductDetailViewModel();
    mdl.product = new AY_PRODUCTS();

    mdl.colors = (from g in db.AY_COLORS select g).ToList();

    return View(mdl);
}

[HttpPost]
public ActionResult ProductsCreate(ProductDetailViewModel prod_)
{
    if (ModelState.IsValid)
    {
        db.AY_PRODUCTS.Add(prod_.product);
        db.SaveChanges();
        int ProductId= prod_.product.ID;

        //HOW CAN I GET THE VALUES OF SELECTED COLORS HERE?

        return RedirectToAction("ProductsCreate");
    }
    else
    {
        return View(prod_);
    }
}

and here is my view which I couldnt complete.

<% foreach (var item in mdl.colors) { %>
    <%: Html.CheckBox( <!-- what exactly ?????? -->) %>
<% } %>

How should I write the view and Action to get the values of selected checkboxes. Please help...