Blue Moon Bay

Little light comes back off a wall this dark, so the blue undertone mostly lives in memory and in direct light rather than in a glance across the room. Vista Paint catalogs it as Blue Moon Bay, 7301.

At LRV 8.0 the walls stop contributing light altogether and the lamps have to do the work. Under warm light it softens; under daylight bulbs it goes hard and flat, with the blue undertone only really visible in the warmer of the two.

Worth checking before committing to a full wall: oranges and warm terracotta nearby - in a floor, a rug, a piece of furniture - will read as a clash here, not a complement, since the two colors sit at opposite ends of the spectrum.

The lighter the trim beside this, the more it will seem to glow - a side effect of the light-reflectance gap rather than anything special about the trim color. The safest multi-color scheme moves from this dark wall to a noticeably lighter secondary tone, then to a near-white ceiling - three genuinely different depths rather than three shades of the same idea (LRV 8.0, 47 and 85, if you're matching by the numbers).

A single accent wall opposite the main window lets daylight hit it directly, which is where a color this dark actually shows its undertone. Behr Cathedral Grey makes a good second wall color here - different enough to read as a real choice, close enough to still feel related (about 396 points apart in light reflectance).

If the wall has any texture or repair work, matte is worth the trade-off even though it holds up to less scrubbing than a satin or eggshell.

Benjamin Moore Newburyport Blue (HC-155) runs close enough - delta-E 1.04 - that swapping brands should not change how the room looks. 4 other-brand colors land within delta-E 2 of this one - a well-populated part of the spectrum with several near-equivalents to choose from.

It is lighter than 4 percent of the Vista Paint range. The name is not unique: Behr S480-5 also sells a color called Blue Moon Bay, and it is not the same shade. Vista Paint lists it in the K codes, alongside 1,318 other colors.