Lawn furniture: more pastels, more comfort, more durability

Vanilla. That is, by far, this season's most stylish neutral when it comes to the finish on poolside, patio, and lawn furniture. If you don't like plain vanilla, take your choice of such trend-setting pastels as powder blue, moss green, mauve, peach, or rose.

If you are shopping for new outdoor furniture this spring, you will discover that it has become far more highly styled and often rather elegant. Silhouettes are trim and sleek. The old bulkiness has gone. Comfort and cushions have been increased. Many materials have been improved. The finishes are more durable, and the assemblages work better.

This year will be ''the year of the glider,'' according to the Summer & Casual Furniture Manufacturers Association, and almost every manufacturer is offering one or several. Made to seat one, two, or more, they will remind many people of childhood summers spent during the era when gliders, with their gentle swaying motion, were standard porch and lawn equipment right across America.

Other ''action'' pieces will include adjustable chaise longues and chairs that swivel.

Most people would like to think that summer furniture will no longer fade, rust, or deteriorate and that it can weather all the elements. But, according to a guide published by Workbench, if you want to leave your furniture outdoors all summer, you should be sure it is made of materials with maximum weather resistance. Dampness is still a major problem for such furniture. So is the sun , which dries out many natural materials and can fade and discolor fabrics and plastics.

Solid redwood is one favorite, because of its remarkable durability. A more recent development is lumber that has been treated to be weather-resistant and is available at lower cost. Other woods must be oiled, painted, or varnished at the start of each summer.

Dampness is the greatest hazard to wicker and rattan, and will cause them to deteriorate. Too much sun will dry them out. A painted or varnished finish will offer some protection, but must be replaced when it chips.

Aluminum is a durable, nonrusting metal, but heavy-alloy aluminums work best outdoors.

Coated steel, as a result of improved technology, has been gaining in popularity and reputation.

Plastics have a strong resistance to moisture, but their reactions to sun and heat vary. Plastic that is reinforced with fiberglass will hold up well over time, but is more expensive.

As for upholstery, no fabric lasts forever when exposed to the weather. Nonporous synthetics are most durable. Look for chairs designed with individually replaceable vinyl or nylon straps, so if a few wear out, you can replace just them.