Portsmouth lands as a medium, muted neutral that holds real depth without crossing into dark territory. Its LRV of 21.9 keeps it grounded and substantial on the wall, well below the airy mid-tones but nowhere near the drama of a deep charcoal or navy. In most rooms it reads as a soft slate-green-gray, the kind of color that feels settled and calm rather than bold or assertive. It carries a quiet sophistication that works in both casual and more polished spaces.
In strong natural light it opens up slightly and lets the green lean breathe, reading closer to a cool sage-influenced gray. Under artificial or low light it pulls inward, becoming more muted and flatter, with the slate quality becoming more pronounced. Reviewers note that in very dark rooms it can lose some of its character and read heavier than intended, which makes testing a large sample in your actual space genuinely important before committing. The color shifts noticeably depending on exposure, so what looks like a blue-gray in one room can read definitively green-gray in another.
The undertone story on Portsmouth is where most of the interesting debate lives. The dominant read from reviewers is a slate-green undertone sitting beneath a neutral gray base, giving the color a quiet, organic quality that separates it from purely cool or purely warm grays. That green presence is subtle but consistent enough that it tends to harmonize well with natural wood tones and earthy materials rather than fighting them.
At least one source describes Portsmouth as reading closer to a deeper blue or near-navy, which appears to be an outlier or a confusion with a darker product. The LRV of 21.9 and the hex firmly place this in mid-tone territory, not dark navy. That said, the blue-gray reading is not completely without basis. In north-facing rooms or under cooler artificial lighting, the green undertone can recede and a cooler blue-gray impression can emerge. The disagreement between reviewers likely reflects genuine light-condition sensitivity rather than anyone being flat-out wrong.
If your space gets a lot of warm incandescent or LED-warm light, expect the green-gray quality to soften and the overall color to feel warmer and more balanced. In cool daylight or shade, lean into testing because that blue-gray shift is real. Sherwin-Williams classifies Portsmouth in the Warms and Neutrals family, which aligns better with the slate-green-gray read than any blue interpretation.
Portsmouth works reliably in living rooms and bedrooms, the two room types our database flags as primary uses, and the research backs that up. In a living room it creates a cozy, grounded atmosphere without feeling heavy or oppressive. Paired with warm wood floors, natural fiber textiles, or leather seating, the slate-green undertone reads as a sophisticated neutral that connects organic materials without competing with them. In a bedroom the muted quality of that LRV 21.9 depth encourages a restful, calm feeling that brighter or cooler grays often undercut.
Beyond those anchor rooms, reviewers also point to kitchens and dining areas where Portsmouth complements wood cabinetry and natural finishes well. The color sits in the Rustic and Refined collection for a reason: it bridges raw, natural textures and cleaner, more transitional settings without looking out of place in either. Its washability and coverage ease make it a practical choice for higher-traffic areas and homes with kids or pets.
Orientation matters here more than with many neutrals. South- and west-facing rooms with warm afternoon light will bring out the green-gray quality and keep the color feeling alive. North- or east-facing rooms may push it toward the cooler, flatter blue-gray reading that some reviewers mention. In very dark rooms with limited natural light, Portsmouth can look more muted and less dynamic than your sample chip suggests. As a whole-house neutral it performs well in connected open-plan spaces where a consistent mid-tone anchor holds rooms together without tipping warm or cool in any jarring way.
Portsmouth brings a calm, settled feeling to a living room without reading dark or moody. It pairs well with warm wood floors and natural fiber rugs, where the slate-green undertone finds common ground with organic textures. Keep trim in a warm creamy white rather than a bright stark white to avoid making the wall color look muddy.
At LRV 21.9 Portsmouth has enough depth to feel cocooning in a bedroom without going oppressively dark. The muted quality works in favor of rest and calm, especially in rooms with soft warm lighting. It reads particularly well with linen bedding and wood furniture, where the slate-green character softens rather than competes.
Reviewers call out kitchens and dining areas as places where Portsmouth earns its keep alongside wood cabinetry and natural finishes. The color holds its own against busy countertop patterns without overwhelming them. In a kitchen with good task lighting, the green-gray lean adds life to what might otherwise be a flat neutral.
Portsmouth's depth at LRV 21.9 gives a dining room enough presence to feel intentional at dinner when lights are lower. The slate-green undertone plays well with wood dining furniture and warm candlelight, which tends to neutralize any cool shift. This is one of the rooms where its Rustic and Refined collection roots show most clearly.
In a home office Portsmouth provides a focused, settled backdrop that does not distract or energize in the wrong ways. The mid-tone depth helps reduce screen glare contrast compared to very light walls. Pay attention to the orientation here because a north-facing office will push the color toward a cooler, flatter read.
Portsmouth coordinates naturally with White Sail, which gives you a clean, warm-leaning white trim option that does not fight the slate-green undertone or read too stark against a mid-tone wall. For a layered tonal approach, Slumber Sloth brings a softer, lighter value into the same color family, working well for an adjacent bedroom or an accent wall that steps down in depth. Stony Creek pulls the earthy, organic quality of Portsmouth further and reads darker and richer, making it a strong choice for a grounding accent or a library-style room that connects to spaces painted in Portsmouth.
Beyond the official coordinates, Portsmouth plays well with warm wood tones, aged brass or matte black hardware, and natural stone surfaces. Because its undertone sits between green and gray, it bridges warm and cool accent colors without forcing a commitment in either direction. Creamy whites work better than bright stark whites at trim, since a high-contrast cool white can make the slate-green quality look muddier than it is.
All comparisons are matched against Portsmouth at LRV 21.9.
High-contrast bright or blue-white trim forces Portsmouth's slate-green undertone to read dull and murky rather than sophisticated. The contrast fights the warmth in the color's neutral base.
Gray tile, cool-toned laminate, or blue-gray flooring can push Portsmouth's already light-sensitive undertone toward a flat, cold blue-gray that most reviewers describe as unintended.
Reviewers specifically flag that in rooms with limited natural light, Portsmouth's LRV 21.9 depth can collapse into a muted, lifeless reading rather than the grounded sophistication it shows in better-lit spaces.
Portsmouth is a medium, muted slate-green-gray with an LRV of 21.9. It reads as a grounded, calm neutral with a quiet green-gray quality, sitting well below airy light grays but not entering dark or moody territory. It belongs to Sherwin-Williams' Warms and Neutrals family and the Rustic and Refined collection.
The primary undertone is slate-green beneath a neutral gray base. Most reviewers land on this green-gray read as the dominant character. In cooler light or north-facing exposures, a blue-gray impression can emerge, which explains why some sources describe it as leaning blue. The green-gray read is the more reliable baseline for warm or mixed light conditions.
Portsmouth sits in a genuinely neutral middle ground. Sherwin-Williams classifies it in the Warms and Neutrals family, which aligns with its slate-green undertone behavior in warm light. In cooler or north-facing light it can shift toward a cooler blue-gray reading. It is not a warm gray in the traditional beige-influenced sense, but it is not a strictly cool gray either.
Portsmouth has an LRV of 21.9. That places it solidly in mid-tone territory, deep enough to read as a substantive color on the wall but not so dark that it overwhelms a room. Spaces with limited natural light will feel the depth more, so testing in your actual conditions is worth the effort.
The official coordinating colors are White Sail for a warm-leaning trim white, Slumber Sloth for a lighter tonal companion, and Stony Creek for a deeper, earthier accent. Beyond those, warm wood tones, aged brass hardware, natural stone, and earthy textiles pair well. Creamy off-whites at trim work better than bright stark whites, which can make the wall color look muddy.
The Sherwin-Williams code is SW 9644. The hex is #768482 and the RGB values are 118, 132, 130. The LRV is 21.9.
Benjamin Moore Sea Salt (2137-40) is a widely cited comparison in the slate-green-gray family at a similar mid-tone depth. It reads slightly more green and less slate than Portsmouth, so the two are close but not identical. Always sample both in your space before deciding.
