Cornwall Slate
The quiet number-neighbor of a Color of the Year, reviewed honestly: why it reads more gray than green, the rooms it flatters, and the light that flattens it.
Jessica has spec'd whites and neutrals for more than 300 rooms and keeps a sample wall of painted drawdowns in her studio. Every color review is checked against real reader rooms in the comments and re-tested when a formula changes. About the testing process →
- 1Black Fox7
- 2Pewter Green12
- 3Cornwall Slate29
- 4Stardew43
- 5Upward57
The Fast Verdict
Cornwall Slate lives in Sherwin-Williams' Green Paint Colors family, one SKU number away from Evergreen Fog — the brand's 2022 Color of the Year.
But its own numbers tell a different story: an even red-green balance and a blue channel only a shade lower is the fingerprint of a warm gray, not a green. In real daylight it reads as an easy, grounded greige with the faintest olive whisper — closer to a safe neutral than a statement sage. In dim rooms that whisper disappears entirely, and that gap between expectation and result is where its bad reviews come from.
Kitchen islands and cabinets that want a hint of green without going full sage · dens and home offices with real daylight · craftsman exteriors with white trim · anyone who wants "gray with a little life" more than an actual green room
You specifically want the Evergreen Fog sage look · your room is north-facing and dim with no lamps · your counters are cool white quartz or marble · you need a color your painter can match from memory — this one needs a fan deck chip in hand
- Reads as an easy, grounded warm gray more often than a committed green — safe for buyers nervous about full sage
- Holds real color at LRV 29 without going murky or dark
- Flatters brass, walnut and cream trim
- A genuine craftsman-exterior classic with white trim
- Quiet enough to be a whole-room backdrop for art and walnut furniture
- Loses its green almost entirely in dim, north-facing light
- Disappoints buyers who actually wanted the Evergreen Fog sage look
- Looks washed out next to a truer, more saturated green
- Needs real daylight to earn its keep — not a safe pick for a dark room
What Color Is Cornwall Slate, Really?
Sherwin-Williams files Cornwall Slate under its Green Paint Colors family, sitting one number away from SW 9130 Evergreen Fog — the brand's famous 2022 Color of the Year. That neighbor status is the whole story, and the deck's own numbers give it away: Cornwall Slate's red and green channels are exactly equal, with blue only twelve points lower. That is the fingerprint of a warm neutral gray, not a green — Evergreen Fog, by comparison, pushes its green channel noticeably above blue. Of the whole 9130-9131 pairing, Cornwall Slate is the one that barely commits to the family name it was filed under.
At LRV 29 it sits in the same mid-depth band as Evergreen Fog and Retreat — deep enough to hold real color on a wall instead of washing out, light enough to still read as a livable neutral rather than a dark accent. That depth is doing real work: a paler gray-green fades to nothing in a bright room, but Cornwall Slate stays present and grounded across most daylight conditions. It just needs that daylight to show what little green it has.
Undertone in one line: warm gray first, a faint olive-green whisper second, never blue, never a true committed sage. If your sample reads flat taupe-gray with no hint of green at all, that is your room's light doing exactly what cool, dim light does to this color — it is not a bad can of paint.
Where It Shines
Give it real daylight — south or west exposure — and warm materials, and Cornwall Slate is a genuinely easy color to live with: a grounded, quiet greige-green that flatters brass, walnut and cream trim without asking the room to commit to "green" the way Evergreen Fog does. Kitchen islands are its best interior use, where the color reads as an intentional, grown-up choice against white perimeter cabinets. Outdoors, on craftsman-style siding with white trim, it does the same job full-size: earthy without going full forest-green.
Where It Fails
Almost every disappointed review of Cornwall Slate comes from one of three predictable situations, and none of them are a defect in the can — they are the color being exactly what its numbers say it is.
Cool daylight is already working against the color's one warm asset — the faint green whisper — and without any warm lamp to compensate, it disappears completely. What is left reads as flat, slightly muddy taupe-gray with none of the earthy quality shown in bright photos. Add warm 2700K lamps or skip this room.
Shoppers chasing the Evergreen Fog look sometimes grab the neighboring SKU by mistake, or simply assume "filed under green" means it will read green on the wall. It mostly doesn't — Cornwall Slate is genuinely closer to gray on the color wheel. If green is the point of the room, go Evergreen Fog or Retreat instead and let this one be the backup plan.
Paint it beside an actually saturated green and Cornwall Slate looks washed-out and unsure of itself by comparison. Paired with cool white quartz or Carrara-style marble, the same effect shows up as a slightly dull, muddy cast rather than the earthy warmth it has in the right kitchen.
Room by Room
Against white perimeter cabinets and brass or matte-black hardware, it reads as a deliberate, grounded choice rather than a loud statement. Satin cabinet enamel; keep the perimeter a warm white like Alabaster, not a stark white.
A quiet backdrop for a desk, walnut shelving and morning light. It is calm without being flat, which is exactly what a work-from-home room needs. Eggshell for durability where a chair meets the wall.
Beautiful as a main-wall or accent color with warm wood furniture and cream textiles. In an open floor plan it has to negotiate with the kitchen's light and finishes, so sample it in the actual room before committing to the whole space.
Restful under warm lamps at night, but a north-facing bedroom with cool bulbs will read colder and grayer than the chip promised. Pair with warm 2700K fixtures if the room does not get real daylight.
With warm stone, wood vanities and brass fixtures it is a strong, grounded choice. Against cool white or blue-gray marble it goes dull rather than earthy — test a large sample above the actual counter first.
On siding with white trim it reads as an easy, earthy neutral in full sun, closer to a stone-gray than a green from the street. Pairs well with a black or near-black front door for contrast.
Your Light Is the Risk
Strong daylight brings out the faint warm-olive whisper and the color reads as a grounded, earthy gray-green all day.
Cool, flat daylight erases what little green there is, leaving a dull, slightly muddy taupe-gray. Test with a large sample here first.
Warmer and greener at the sun hours, quieter and grayer the rest of the day. The shift is gentle, not a color change most people mind.
2700K lamps pull it warmer and more olive; cool white LEDs flatten it back toward plain gray. Swap the bulbs before you swap the paint.
Most complaints about Cornwall Slate are a light mismatch. Upload a photo of your actual room and see it on your walls — then ask for the same wall in north light or evening lamps before you buy a single sample.
Need It From Another Brand?
Any paint counter can custom-tint Sherwin-Williams SW 9131 directly. If you would rather stay in one brand's own deck, these are the closest stock matches, measured as ΔE2000. Under 2 is a difference you will not see on the wall.
| Brand | Closest color | ΔE | LRV | |
|---|---|---|---|---|
| Behr | Shady WillowECC-36-1 · Behr | 1.7 | 30 | Color page → |
| Benjamin Moore | Storm Cloud Gray2140-40 · Benjamin Moore | 1.4 | 29 | Color page → |
| Valspar | Gray Expose5007-2A · Valspar | 1.1 | 30.6 | Color page → |
| PPG / Glidden | Steeped TeaPPG0999-4 · PPG / Glidden | 2.9 | 30 | Color page → |
| Glidden | Steeped TeaPPG0999-4 · Glidden | 2.7 | 30 | Color page → |
| HGTV Home by Sherwin-Williams | Marsh GrassesHGSW 3274 · HGTV Home by Sherwin-Williams | 0.0 | 29 | Color page → |
Similar Sherwin-Williams Colors
The nearest shades to Cornwall Slate within Sherwin-Williams's own range, ranked by perceptual color distance — useful when you want the same look a touch lighter, darker, or warmer.
WCAG 2.1: AA is 4.5 : 1 for normal text, 3 : 1 for large text, AAA is 7 : 1.
Cornwall Slate vs the Colors You're Also Considering
Every Cornwall Slate sample board has the same rivals on it. The numbers show the real lightness gap — then it comes down to which risk you would rather live with.
Pick this for the quieter, grayer version of the same family, easier to live with if green makes you nervous.
Sherwin-Williams SW 9130 · LRV 30Evergreen FogPick this if you actually want the green — Evergreen Fog commits to sage where Cornwall Slate hedges toward gray.
Pick this for the lighter, more neutral version that reads as gray in more rooms than Retreat ever will.
Sherwin-Williams SW 6207 · LRV 21RetreatPick this for a deeper, more saturated cabinet green with real conviction, not a hint of one.
Cornwall Slate Coordinating Colors
The rule for coordinating with Cornwall Slate: warm whites and other muted greige-greens work with it, cold whites and saturated colors fight it. It pairs best with the same family of quiet neutrals SW recommends on its own site, plus one true dark for contrast. These are the partners that keep showing up in rooms that work:
The Quiet Number-Neighbor of a Color of the Year
Sherwin-Williams' Green Paint Colors family runs SW 9130 through the low 9100s, and Cornwall Slate — SW 9131 — sits directly beside SW 9130 Evergreen Fog, the color that became the brand's 2022 Color of the Year and one of the most-searched greens of that decade. Evergreen Fog got the campaign, the magazine features, the kitchen-island fame. Its next-door neighbor never got a moment of its own.
That obscurity is not a mark against it. Read its own numbers and Cornwall Slate is arguably the more broadly livable color of the two: a warm gray with a whisper of the same family DNA, rather than a committed sage that not every room, or every buyer, wants to commit to. It is the color you reach for when you liked the idea of Evergreen Fog more than you liked the idea of a genuinely green room.
Cornwall Slate With Wood Tones and Floors
Warm wood is the easy answer here. Walnut, white oak and cedar all sit comfortably against Cornwall Slate because both land in the same earthy, muted register — neither fights the other for attention. Honey oak works too, more forgivingly than it does with a true green or a cool gray, since Cornwall Slate's warmth meets golden wood roughly halfway.
The floors that need a sample first are cool gray-washed wood and cool white LVP. Against a cold gray floor, the color's already-faint green whisper can vanish entirely, leaving a flat, slightly lifeless gray-on-gray room. Metals are straightforward: brass and matte black both read well against it; polished chrome is the one finish that leans noticeably colder than the paint around it.
Three Ready Palettes Built on Cornwall Slate
A color is never alone on the wall. These are complete combinations in the 60-30-10 pattern, with the reason each one holds together. Every one opens in the visualizer.
Alabaster keeps the perimeter soft and warm so the Cornwall Slate island reads as a deliberate accent instead of a mismatch. Iron Ore on the hood gives the kitchen one true dark note, and brass or matte-black hardware ties the greige-green island back to it.
Try this palette in your roomWhite trim keeps the earthy siding from reading too dark from the street, and a near-black door adds the single sharp contrast a craftsman facade wants. This combination reads stone-gray more than green in full sun — plan for that if a green house is the goal.
Try this palette in your roomRetreat is Cornwall Slate's deeper, greener cousin, so layering it inside built-ins reads as one tonal family getting quieter, not a color change. Alabaster trim keeps the room from feeling closed in, which matters most in a room with a north-facing desk.
Try this palette in your roomCornwall Slate FAQ
Is Cornwall Slate more gray or more green?
More gray, honestly. Sherwin-Williams files it under the Green Paint Colors family because it sits next to Evergreen Fog on the fan deck, but its RGB numbers are the fingerprint of a warm neutral gray — an even red-green balance with blue only a shade lower. In good daylight you'll see a faint olive whisper; in dim light it can read as plain gray.
What's the difference between Cornwall Slate and Evergreen Fog?
They sit one SKU number apart and share the same mid-depth, but Evergreen Fog pushes its green channel clearly above blue, so it reads as an actual sage. Cornwall Slate's channels are far more balanced, which is why it reads as a quiet warm gray with only a hint of green rather than a committed green.
Does Cornwall Slate work on kitchen cabinets?
Yes, especially on an island against white perimeter cabinets — it reads grounded and intentional rather than loud. Use a satin, urethane-fortified cabinet enamel and keep the rest of the kitchen a warm white, not stark white, so the color doesn't look washed out by comparison.
What trim color goes with Cornwall Slate?
A warm white handles it best — Sherwin-Williams' own trim suggestions lean toward Agreeable Gray or Balanced Beige, and a soft warm white like Alabaster or Pure White works just as well. Avoid a cold, blue-white trim, which pushes the wall color toward dull by contrast.
Is Cornwall Slate good for an exterior?
Yes — it's a solid craftsman-style siding choice, reading as an earthy stone-gray in full sun with white trim and a dark door for contrast. Expect it to lean gray rather than green from the street; if you want visible green on the house, Evergreen Fog is the more committed choice.
Does Cornwall Slate need warm light to look right?
It needs real daylight more than it needs warm light specifically. In a bright south- or west-facing room it holds its earthy, grounded character; in a dim, north-facing room with cool bulbs, the faint green disappears and it reads as flat gray. Warm 2700K lamps help but won't fully replace daylight.
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