Deep Lagoon

Neutral enough to sit under other colors, with a blue cast underneath. Vista Paint files it as 0507.

Chroma 6.9 means the color content is small, which is exactly why the blue cast matters so much - there is nothing else here to distract from it. A warm bulb is the easiest fix if this reads colder than expected once it is on the wall.

LRV 17.0 - comfortably in the range that suits a whole room rather than one wall. Open-plan walls, hallways, anywhere the color has to work in several exposures at once.

For a secondary wall, Behr Silver Bullet gives a natural step up in brightness without feeling like a mismatch (roughly 39 LRV points apart).

Benjamin Moore Britannia Blue (1623) matches it closely enough that no one will tell them apart on a wall. 3 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. This color reads consistently across most finishes, so the choice can come down to durability needs rather than how it changes the color.

It is lighter than 15 percent of the Vista Paint range. The name is not unique: Dunn-Edwards DE5740 also sells a color called Deep Lagoon, and it is not the same shade. Among grays it is one of the strongest: only 1 percent of them carry more colour. Vista Paint lists it in the C codes, alongside 1,421 other colors.