The sample code

app.js

var win = Ti.UI.createWindow({
    title: '1. Look @ White Table',
    backgroundColor: '#000'
});
var dat = [];
var table = Ti.UI.createTableView({
   
    data:dat,
    separatorColor: 'blue'
});
win.add(table);

var addRow = Ti.UI.createButton({
    bottom: 0, height: 50,
    title: '2. Click Me'
});
addRow.addEventListener('click', function() {
    table.appendRow({ title: '3. Look @ My Separator' });
});
win.add(addRow);

var tabGroup = Ti.UI.createTabGroup();
tabGroup.addTab(Ti.UI.createTab({
    navBarHidden:true,
    window: win
}));
win.hideNavBar();
tabGroup.open();