# #1f3851

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

## Values

- Hex: `#1f3851`
- RGB: rgb(31, 56, 81)
- HSL: hsl(210, 45%, 22%)
- OKLCH: oklch(0.333 0.054 249.8)
- Relative luminance: 0.0371
- Nearest named color: Astral Nomad (#203943, Δ 2.66) — https://brandsweets.com/colors/astral-nomad
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/1f3851

## Tints & shades

- Tints (toward white): #2a4d6f, #345e89, #3f73a6, #4e85bc, #6b99c7, #89add2, #a3bfdc, #c0d4e7, #dae6f1, #f8fafc
- Shades (toward black): #1c334a, #192e43, #182b3f, #152637, #122130, #0f1c29, #0d1721, #0b141e, #080f16, #060a0f

## Harmonies

- Complementary: #51381f
- Analogous: #1f5151, #1f1f51
- Triadic: #511f38, #38511f
- Split-complementary: #511f1f, #51511f
- Tetradic: #511f51, #51381f, #1f511f

## Colors that go with #1f3851

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

- **Dark Olive Green** #556b2f [harmony, pool: triadic] — Dark Olive Green completes a triad with #1f3851 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove), 7-Eleven (https://brandsweets.com/colors/brands/7-eleven-com), Oatmeal (https://brandsweets.com/palettes/neutral#oatmeal), Undergrowth (https://brandsweets.com/palettes/dark#undergrowth). — https://brandsweets.com/colors/darkolivegreen
- **Teal** #008080 [harmony, pool: analogous] — Teal is #1f3851's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Stanley (https://brandsweets.com/colors/brands/stanley1913-com), N26 (https://brandsweets.com/colors/brands/n26-com), Gusto (https://brandsweets.com/colors/brands/gusto-com), Mid-Century (https://brandsweets.com/palettes/warm#mid-century). — https://brandsweets.com/colors/teal
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #1f3851 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove). — https://brandsweets.com/colors/sienna
- **Amber** #ffbf00 [pool] — Amber is paired with #1f3851 in 5 real palettes, including Beach Hut and McDonald's's brand system, as the supporting colour. Seen in: Beach Hut (https://brandsweets.com/palettes/light#beach-hut), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Southwest Airlines (https://brandsweets.com/colors/brands/southwest-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 12 real palettes, including Alaska Airlines's brand system and Jeep's brand system put Blue beside #1f3851, as the accent. Seen in: Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Jeep (https://brandsweets.com/colors/brands/jeep-com), Minecraft (https://brandsweets.com/colors/brands/minecraft-net), Headspace (https://brandsweets.com/colors/brands/headspace-com). — https://brandsweets.com/colors/blue
- **Blush Pink** #e8b4b8 [pool] — 5 real palettes, including Rain Garden and Garden Wedding put Blush Pink beside #1f3851, as the accent. Seen in: Rain Garden (https://brandsweets.com/palettes/cool#rain-garden), Garden Wedding (https://brandsweets.com/palettes/light#garden-wedding), Blush (https://brandsweets.com/palettes/light#blush), Nursery (https://brandsweets.com/palettes/light#nursery). — https://brandsweets.com/colors/blush-pink
- **Burlywood** #deb887 [pool] — Burlywood is paired with #1f3851 in 4 real palettes, including Coastal and Polaroid, as the accent. Seen in: Coastal (https://brandsweets.com/palettes/cool#coastal), Polaroid (https://brandsweets.com/palettes/light#polaroid), Chalkboard (https://brandsweets.com/palettes/dark#chalkboard), Kiln (https://brandsweets.com/palettes/dark#kiln). — https://brandsweets.com/colors/burlywood
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #1f3851: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy. — https://brandsweets.com/colors/whitesmoke

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

- On white (#ffffff): 12.05:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.74:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #4278ae (4.53:1); AA: background → #a1a1a1 (4.66:1); AAA: text → #6b99c7 (7.01:1); AAA: background → #c7c7c7 (7.13:1)

## Brands using this color

- **Boeing** — primary #253746 (Δ 1.983) — https://brandsweets.com/colors/brands/boeing-com

## Curated palettes containing it

- **Frost & Ember** (winter, bold, cool, vivid) — #1d3557, #a8dadc, #e63946, #f1faee — Navy and frost with one ember red — the classic cold-with-a-warm-accent structure, borrowed from a thousand ski posters. — tool: https://brandsweets.com/palettes/new/1d3557-a8dadc-e63946-f1faee — collection: https://brandsweets.com/palettes/winter

## 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/1f3851-9cabc4-df514e-1f202d-e9f1f1?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: "#1f3851" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.