# #1b375f

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

## Values

- Hex: `#1b375f`
- RGB: rgb(27, 55, 95)
- HSL: hsl(215, 56%, 24%)
- OKLCH: oklch(0.337 0.079 257.5)
- Relative luminance: 0.0379
- Nearest named color: Atlantic Navy (#13336f, Δ 3.302) — https://brandsweets.com/colors/atlantic-navy
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/1b375f

## Tints & shades

- Tints (toward white): #23487b, #2c5a9b, #346ab7, #487fcb, #6492d3, #80a6db, #a0bce4, #bbd0ec, #dbe6f5, #f7f9fd
- Shades (toward black): #193358, #162e50, #142a48, #122540, #102038, #0d1c30, #0b1728, #091220, #070e18, #040910

## Harmonies

- Complementary: #5f431b
- Analogous: #1b5a5f, #211b5f
- Triadic: #5f1b37, #375f1b
- Split-complementary: #5f211b, #5a5f1b
- Tetradic: #5f1b5a, #5f431b, #1b5f21

## Colors that go with #1b375f

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

- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #1b375f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Asana (https://brandsweets.com/colors/brands/asana-com), Subaru (https://brandsweets.com/colors/brands/subaru-com), Mushroom (https://brandsweets.com/palettes/neutral#mushroom). — https://brandsweets.com/colors/seagreen
- **Teal** #008080 [harmony, pool: analogous] — Teal is #1b375f'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), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), N26 (https://brandsweets.com/colors/brands/n26-com), Gusto (https://brandsweets.com/colors/brands/gusto-com). — https://brandsweets.com/colors/teal
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #1b375f 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 #1b375f in 4 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 #1b375f, 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), Monzo (https://brandsweets.com/colors/brands/monzo-com). — https://brandsweets.com/colors/blue
- **Blush Pink** #e8b4b8 [pool] — 5 real palettes, including Rain Garden and Garden Wedding put Blush Pink beside #1b375f, 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
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #1b375f: 7 real palettes, including Open House and Coastal, as the supporting colour. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Coastal (https://brandsweets.com/palettes/cool#coastal), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty), Dusk (https://brandsweets.com/palettes/cool#dusk). — https://brandsweets.com/colors/cadetblue
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #1b375f: 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): 11.94:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.76:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #3c76c8 (4.62:1); AA: background → #a1a1a1 (4.62:1); AAA: text → #6c98d5 (7.09:1); AAA: background → #c7c7c7 (7.06:1)

## Brands using this color

- **Confluent** — primary #143464 (Δ 1.59) — https://brandsweets.com/colors/brands/confluent-io
- **Marvel** — secondary #223364 (Δ 1.756) — https://brandsweets.com/colors/brands/marvel-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/1b375f-9ca8c4-df5d4e-201f2d-e9f0f1?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: "#1b375f" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.