change the color of datagrid

I have one selectall checkbox on grid which selects all the checkboxes for each row in the grid. I have written JS function for it. Not I want the backcolor of the grid to be changed on the event. How do I do that in the JS? Or any other way??

Here is my JS function:

function SelectAllCustomers()
{
// Iterate through the datagrid item (starting from 2).
for (i=2; true; i++)
{
// Get the id of the checkbox for that row.
//var id = "_ctl0_ctlCustomerImpact_dgCustomersImpacted__ctl" + i + "_chkCustomer";
var id = "dgTest__ctl" + i + "_chkCustomer";
// Check if id exists.
if (document.getElementById(id) != null)
{
// If found, set / unset its checked property based on the checked property of Select all checkbox.
document.getElementById(id).checked = document.getElementById('chkAllCustomers').checked;

}
else
{
// Else, exit the loop.
break;
}
}
}