Homeowners choose finish color from a sample the size of a coaster, which is an unfair way to make a decision that determines what the pool looks like every day for the next fifteen years.
The water color is not the finish color
Water depth, sunlight and sky reflection all change the apparent color. A finish that looks mid-grey on a sample reads as deep blue-green in eight feet of water and much lighter in the shallow end of the same pool.
Ask to see finished pools, not samples. Any builder with recent work can point you at two or three, and twenty minutes standing beside a finished pool is worth more than an afternoon with a color chart.
Light finishes
White and light grey read as bright, clear, resort-like blue. They show the floor clearly, which parents generally prefer. They also show every leaf, every bit of debris and every stain, and they reflect more heat, so the water runs slightly cooler.
Mid and dark finishes
Darker greys, blues and blacks read as deeper and more natural, and they hide debris well. They absorb more heat, which in North Carolina meaningfully extends the comfortable season at both ends — worth something real in April and October.
The tradeoff is visibility. A dark finish makes it harder to see the bottom, which matters for safety with young children and matters for spotting problems early. Some homeowners also find that dark finishes show scale and calcium more obviously than they expected.
Aggregate versus plain plaster
Plain plaster is the least expensive and the shortest-lived, typically wanting resurfacing sooner. Exposed and polished aggregate finishes cost more up front, last considerably longer, and hide minor imperfections and staining better because the surface is not uniform.
Over a full ownership period the aggregate finishes usually cost less per year, which is the comparison that matters.
How finishes age
Every finish changes. Plaster mottles. Aggregate darkens slightly. Both are affected by water chemistry more than by anything else — a pool run at consistent chemistry ages evenly, and a pool run carelessly develops the patchiness people blame on the finish.
If a uniform appearance over many years matters to you, that is an argument for aggregate and for automation that keeps chemistry steady.
The practical advice
Choose the color with the water in mind rather than the sample, weight visibility according to who will be swimming, and remember that a mid-tone is the safest choice for anyone who is genuinely unsure.
Waterline tile is part of the same decision
Tile at the waterline is what your eye actually reads at the pool edge, and it either complements the finish or fights it. Choosing them together, from samples viewed side by side, produces a better result than choosing the finish and then picking tile from a different showroom weeks later.
Glass tile reads brighter and more saturated; ceramic and porcelain are more muted and considerably less expensive. Darker tile hides the calcium line that eventually forms; lighter tile shows it. That last point is worth weighting if your fill water is hard.
Coping colour matters more than people expect
The coping frames everything. A cool grey coping against a warm-toned deck looks unresolved, and a coping that matches the deck exactly can read flat. Getting a physical sample of coping, decking and tile together, outdoors, in daylight, is the single most useful hour in the selection process.
How light changes it through the day
The same pool reads differently at ten in the morning, at two in the afternoon and at dusk. Overcast days flatten everything and bright sun saturates it. If you look at a finished pool as a reference, try to see it at the time of day you will use yours most.
Pools on shaded lots read considerably darker than the same finish in open sun, which is worth knowing on wooded lots around Browns Summit or Clemmons. A mid-tone that looks right in a sunny showroom photo can read almost black under a canopy.
Repairs and patching
One practical argument for aggregate over plain plaster: when a repair is needed, an aggregate finish hides the patch far better. Plain plaster patches are visible for the life of the finish, because new plaster and aged plaster never match.
On a pool likely to need occasional repair — an older shell, a busy family pool, anywhere with hard water — that is a real consideration rather than a theoretical one.