Richly colored fruits and vegetables, such as those available fresh in New York from now through the fall, are colorful and tasteful additions to your table, and also vital to a healthy diet.

Nutrition research shows that colorful fruits and vegetables—dark green, deep red, purple, bright orange and yellow—contain essential vitamins, minerals, fiber and phytochemicals needed by the human body. In addition, the pigments—the very things that make carrots and pumpkins orange and plums purple—may themselves protect against chronic diseases, including cancer and heart disease.

By putting colorful vegetables and fruits, for example, lettuce and plums, on your plate or in your lunch bag, you are more likely to eat the recommended five to nine servings of vegetables and fruits every day.

Most dark green lettuces are good sources of vitamin C, beta-carotene, iron, calcium, folate and dietary fiber. In general, the darker the greens, the more nutritious the leaf. And you get a lot of leaf—one and a half cups of chopped raw lettuce—for approximately 15 calories and zero grams of fat.

Because lettuce is delicate, great care should be taken in selecting and storing it. Leaves should be fresh and crisp, with no signs of wilting or dark spots. The darker outer leaves are the most nutritious.

Lettuce tends to keep well in plastic bags in the crisper section of the refrigerator. Romaine lettuce generally lasts approximately 10 days, and the butterhead and endive lettuces last approximately four days. Very delicate greens do not last long; so buy only as much as needed at one time and use it immediately.

Leaves that have roots should be placed in a glass container of water with a bag over the leaves, and then stored in the refrigerator. Salad greens should not be stored near apples and other fruits that produce ethylene gases, because this exposure will increase brown spots on the lettuce and causes the lettuce to spoil sooner. All lettuce should be thoroughly washed to remove dirt and any insects.

Here are some tips for making lettuce a part of everyday meals:

  • Add lettuce to all sandwiches.
  • Try different mixes of lettuce for variety.
  • Spritz some olive oil onto romaine or radicchio leaves and grill until slightly soft.
  • Use any variety of lettuce as edible plate liners.

Plums come in a wide variety of shapes, sizes and skin colors, including crimson, blue and purple. The flesh is usually yellow or reddish. Plums are low in fat and calories, free of sodium and cholesterol and a good source of vitamin C.

Plums should be plump. If a fruit yields to gentle pressure, it is ready to eat. Plums that are firm (but not rock hard) can become softer but will not get any sweeter. To soften hard plums, put several in a loosely closed paper bag and let them stay there at room temperature for one or two days. Ripe plums can be stored in the refrigerator up to three days. Plums are juiciest at room temperature. Always wash them before eating or cooking them.

Follow these tips to make plums a part of a daily diet:

  • Chop plums into a fruit salad.
  • Add plums to broiled or grilled fish.
  • Use plums as part of fruit toppings for frozen yogurt, waffles and pancakes.