last question for the night, I promise
given this code:

Ext.define('Sports.view.customer.List' ,{
extend: 'Ext.grid.Panel',
alias : 'widget.customerlist',
store: 'Customers',

title : 'All Customers',

initComponent: function() {

this.columns = [
{header: 'Name', dataIndex: 'Name', flex: 1, field: 'textfield'},
{header: 'Address', dataIndex: 'Address', flex: 1, field: 'textfield'},
{header: 'City', dataIndex: 'City', flex: 1, field: 'textfield'},
{header: 'State', dataIndex: 'State', flex: 1, field: 'textfield'}
];

this.callParent(arguments);
}
});

it brings up a nice "grid" (is it a grid?) widget, with rows having an alternative colour. How do I change the row colours ? I know it's in a css file, but I don't know the class or format of the css file that I need to create.

thanks.