Light colors are best, because they reflect the light. Drink plenty of fluids, generally at least eight glasses a day. Have a tall glass before you start exercising, a cup every 20 minutes during the activity, and another tall glass when you're finished. Even though we perspire less with age, a lot of water is still lost as sweat. Tap water, fruit drinks, and vegetable drinks all work well.
Some folks prefer commercial sports drinks.
They help to replace the salt and potassium lost in sweat. But avoid alcohol and caffeine, which make you lose water. Also remember, the loss of water can cause serious problems by raising the body temperature and placing dangerous demands on the circulation. So force yourself to drink a little more than you want. And don't wait until you are thirsty.