# #151b37

A color — cool, dark, luxury, bold, modern. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#151b37`
- RGB: rgb(21, 27, 55)
- HSL: hsl(229, 45%, 15%)
- OKLCH: oklch(0.233 0.055 272.4)
- Relative luminance: 0.0122
- Nearest named color: Nightwalker (#161d3b, Δ 0.964) — https://brandsweets.com/colors/nightwalker
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/151b37

## Tints & shades

- Tints (toward white): #202a55, #2d3a76, #384994, #4358b1, #6072c3, #7e8cce, #9ba7d9, #b9c1e4, #dadef1, #f8f8fc
- Shades (toward black): #141a34, #121830, #11162c, #0f1429, #0e1225, #0b0f1e, #0a0d1a, #080b16, #070912, #06070f

## Harmonies

- Complementary: #373115
- Analogous: #152d37, #201537
- Triadic: #37151b, #1b3715
- Split-complementary: #372015, #2d3715
- Tetradic: #37152d, #373115, #153720

## Colors that go with #151b37

Named partners (harmony on the OKLCH wheel, co-occurrence in curated palettes and brand systems, and the neutrals that carry it), best first:

- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #151b37: softer than #000 and cool enough to feel like part of the same palette. Seen in: Volkswagen (https://brandsweets.com/colors/brands/vw-com), Asana (https://brandsweets.com/colors/brands/asana-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool). — https://brandsweets.com/colors/charcoal
- **Dark Olive Green** #556b2f [harmony, pool: complementary] — Dark Olive Green sits directly opposite #151b37 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Cohere (https://brandsweets.com/colors/brands/cohere-com), Warp (https://brandsweets.com/colors/brands/warp-dev), 7-Eleven (https://brandsweets.com/colors/brands/7-eleven-com), Magazine Ochre (https://brandsweets.com/palettes/editorial#magazine-ochre). — https://brandsweets.com/colors/darkolivegreen
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #151b37 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Asana (https://brandsweets.com/colors/brands/asana-com), Subaru (https://brandsweets.com/colors/brands/subaru-com), Kia (https://brandsweets.com/colors/brands/kia-com), Next.js (https://brandsweets.com/colors/brands/nextjs-org). — https://brandsweets.com/colors/seagreen
- **Sienna** #a0522d [harmony, pool: split] — Sienna is a split-complement of #151b37: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Woodsmoke (https://brandsweets.com/palettes/dark#woodsmoke), Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar), BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Oatly (https://brandsweets.com/colors/brands/oatly-com). — https://brandsweets.com/colors/sienna
- **Slate Blue** #6a5acd [harmony, pool: analogous] — Slate Blue is #151b37's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Indigo SaaS (https://brandsweets.com/palettes/modern#indigo-saas), Sentry (https://brandsweets.com/colors/brands/sentry-io), GitLab (https://brandsweets.com/colors/brands/gitlab), Superhuman (https://brandsweets.com/colors/brands/superhuman-com). — https://brandsweets.com/colors/slateblue
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #151b37's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Discover (https://brandsweets.com/colors/brands/discover-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/steelblue
- **Amber** #ffbf00 [pool] — Amber is paired with #151b37 in 18 real palettes, including Southwest Airlines's brand system and Blueprint, as the accent. Seen in: Southwest Airlines (https://brandsweets.com/colors/brands/southwest-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 21 real palettes, including Monzo's brand system and League of Legends's brand system put Blue beside #151b37, as the accent. Seen in: Monzo (https://brandsweets.com/colors/brands/monzo-com), League of Legends (https://brandsweets.com/colors/brands/leagueoflegends-com), Warp (https://brandsweets.com/colors/brands/warp-dev), Penpot (https://brandsweets.com/colors/brands/penpot-app). — https://brandsweets.com/colors/blue

## Contrast (WCAG 2.x, as text)

- On white (#ffffff): 16.88:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.24:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6072c3 (4.69:1); AA: background → #858585 (4.58:1); AAA: text → #8593d1 (7.09:1); AAA: background → #a8a8a8 (7.1:1)

## Brands using this color

- **Southwest Airlines** — secondary #111b40 (Δ 1.805) — https://brandsweets.com/colors/brands/southwest-com

## Curated palettes containing it

- **Fintech Trust** (cool, clean, modern) — #0b3d91, #4b6a9b, #00a878, #ffffff, #0b1f3a — Navy signals custody and stability; the green accent is money moving the right way. No red anywhere except errors. — tool: https://brandsweets.com/palettes/new/0b3d91-4b6a9b-00a878-ffffff-0b1f3a — collection: https://brandsweets.com/palettes/cool

## Fonts for this mood

- luxury: https://brandsweets.com/fonts/mood/luxury
- bold: https://brandsweets.com/fonts/mood/bold
- modern: https://brandsweets.com/fonts/mood/modern

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/151b37-9c9fc4-df7e4e-231f2d-e9eef1?lock=0&style=vibrant
(Humans lock/regenerate in the tool; the URL is the state — read `lock=` back to see what they kept.)

## Connect an agent

Point any MCP client at the BrandSweets colors endpoint for the same engine:

- Endpoint: https://mcp.brandsweets.com/colors/mcp
- Tools: `analyze_color` (e.g. `analyze_color({ color: "#151b37" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.