Before you buy anything in a neutral color for outside, run a hand over the actual sample in daylight, not the showroom lighting that makes every greige look identical. Sun shifts these tones more than indoor furniture ever gets tested for, and a cushion fabric that looks like oatmeal in the store can go the color of wet cardboard after one summer on a bright patio. Check the swatch outdoors if you can, even just holding it up by the car park.
The appeal of neutral pieces is that they stop fighting with everything else out there, the terracotta pots, the green of whatever you've managed to keep alive, the brick or decking underneath. A warm sand or driftwood gray frame sits quietly against most backdrops, which matters more outside than in, because you can't just shut the door on a clashing patio the way you can a room. It also means you're not locked into one cushion color forever. Swap the cushions, change the mood, keep the bones.
The frame is where the real differences show up, and most of them you can check with your hands before you pay for anything. Run your fingers along a weld or a joint, there should be no sharp seam or visible glue line. For aluminum, look for powder coating that feels slightly textured and even, not a thin shiny spray that will chip the first time a chair gets dragged across stone. For wood, FSC certified teak or eucalyptus with a tight, straight grain will silver evenly and predictably, while cheaper mixed hardwoods go patchy and gray in blotches within a season. Wicker should be woven tight enough that you can't easily push a finger through, and the resin strands should feel slightly flexible rather than brittle, brittle means it will crack the first cold snap it meets. Give any chair a firm shake at the arm, wobble in the showroom is wobble forever.
Where this works best is any outdoor space that gets used across seasons rather than just the two good weeks of early summer, covered porches, patios with some shade, courtyards in milder climates where furniture stays out most of the year. In a small rented backyard a lighter neutral piece also does the trick of making a cramped space look less cluttered, which matters more than people think once you've got a grill, a few pots and maybe a dog bed all competing for the same ten feet.
Measure your doorway or side gate before delivery day, more neutral outdoor sets get returned for not fitting through a narrow side passage than for any color complaint.