If in doubt about whether your windows are the low-E type, consult the manufacturer, dealer or installer. You can also block out the sun, quite easily and with little expense, with window blinds. Christaldi recommended white plastic blinds. Other types of blinds, drapes and shutters are effective at keeping out the sun's heat. Light-colored blinds and drapes, which reflect the sunlight, are best.
Awnings are another, but relatively expensive, method for keeping out the sun's heat.
Another option is so-called solar screen, sold at some home centers. This is a coarse screen that blocks out some sunlight as well as insects. The stucco on our house has faded. A Stucco can be painted, but it isn't always a good idea, since painting will probably mean additional future maintenance to keep the paint in good condition. Stucco that is discolored but in good condition can often be restored to a good appearance by a light pressure-washing.