# #183a3f

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

## Values

- Hex: `#183a3f`
- RGB: rgb(24, 58, 63)
- HSL: hsl(188, 45%, 17%)
- OKLCH: oklch(0.325 0.04 208.1)
- Relative luminance: 0.0358
- Nearest named color: Royal Neptune (#1c3b42, Δ 0.764) — https://brandsweets.com/colors/royal-neptune
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/183a3f

## Tints & shades

- Tints (toward white): #23555c, #2e707a, #3a8b98, #45a6b5, #64b7c4, #81c5cf, #9fd3db, #bce0e6, #daeef1, #f8fcfc
- Shades (toward black): #16363b, #142f34, #122c30, #11292c, #0f2529, #0d1f21, #0b1b1e, #0a181a, #071112, #060e0f

## Harmonies

- Complementary: #3f1d18
- Analogous: #183f31, #18263f
- Triadic: #3f183a, #3a3f18
- Split-complementary: #3f1826, #3f3118
- Tetradic: #31183f, #3f1d18, #263f18

## Colors that go with #183a3f

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

- **Rust** #b7410e [harmony, pool: complementary] — Rust sits directly opposite #183a3f on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: IHG (https://brandsweets.com/colors/brands/ihg-com), Harvest (https://brandsweets.com/palettes/warm#harvest), Magazine Ochre (https://brandsweets.com/palettes/editorial#magazine-ochre), Trailhead (https://brandsweets.com/palettes/warm#trailhead). — https://brandsweets.com/colors/rust
- **Sienna** #a0522d [harmony, pool: split] — Sienna is a split-complement of #183a3f: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove), Harvest (https://brandsweets.com/palettes/warm#harvest), BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Woodsmoke (https://brandsweets.com/palettes/dark#woodsmoke). — https://brandsweets.com/colors/sienna
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #183a3f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Astro (https://brandsweets.com/colors/brands/astro-build), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Auth0 (https://brandsweets.com/colors/brands/auth0-com), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: analogous] — Teal is #183a3f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: N26 (https://brandsweets.com/colors/brands/n26-com), Stanley (https://brandsweets.com/colors/brands/stanley1913-com), Mid-Century (https://brandsweets.com/palettes/warm#mid-century), Alpine (https://brandsweets.com/palettes/cool#alpine). — https://brandsweets.com/colors/teal
- **Amber** #ffbf00 [pool] — Amber is paired with #183a3f in 8 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), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org), Google (https://brandsweets.com/colors/brands/google-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 14 real palettes, including Jeep's brand system and Instacart's brand system put Blue beside #183a3f, as the accent. Seen in: Jeep (https://brandsweets.com/colors/brands/jeep-com), Instacart (https://brandsweets.com/colors/brands/instacart-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 #183a3f, 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
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #183a3f: 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): 12.24:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.72:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #35818d (4.68:1); AA: background → #9e9e9e (4.57:1); AAA: text → #43a3b1 (7.11:1); AAA: background → #c4c4c4 (7.02:1)

## Brands using this color

- **Logitech** — accent #0d3a38 (Δ 1.677) — https://brandsweets.com/colors/brands/logitech-com

## 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/183a3f-a2b7be-df4e81-1f252d-e9f1ee?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: "#183a3f" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.