# #1d4e59

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

## Values

- Hex: `#1d4e59`
- RGB: rgb(29, 78, 89)
- HSL: hsl(191, 51%, 23%)
- OKLCH: oklch(0.396 0.055 215)
- Relative luminance: 0.0643
- Nearest named color: Raging Thunderstorm (#004f63, Δ 2.006) — https://brandsweets.com/colors/raging-thunderstorm
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/1d4e59

## Tints & shades

- Tints (toward white): #276977, #2f8092, #399bb1, #4aaec4, #69bcce, #84c8d7, #a3d6e1, #bee2ea, #dceff4, #f7fcfd
- Shades (toward black): #1a4751, #184049, #153941, #13333a, #112f36, #0f282e, #0c2227, #0a1b1f, #071417, #050d0f

## Harmonies

- Complementary: #59281d
- Analogous: #1d5946, #1d3059
- Triadic: #591d4e, #4e591d
- Split-complementary: #591d30, #59461d
- Tetradic: #461d59, #59281d, #30591d

## Colors that go with #1d4e59

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

- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #1d4e59's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Auth0 (https://brandsweets.com/colors/brands/auth0-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), Capital One (https://brandsweets.com/colors/brands/capitalone-com), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: analogous] — Teal is #1d4e59's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Gusto (https://brandsweets.com/colors/brands/gusto-com), Stanley (https://brandsweets.com/colors/brands/stanley1913-com), N26 (https://brandsweets.com/colors/brands/n26-com), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold). — https://brandsweets.com/colors/teal
- **Rust** #b7410e [harmony, pool: complementary] — Rust sits directly opposite #1d4e59 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), Trailhead (https://brandsweets.com/palettes/warm#trailhead). — https://brandsweets.com/colors/rust
- **Blue** #0000ff [pool] — 9 real palettes, including Jeep's brand system and Alaska Airlines's brand system put Blue beside #1d4e59, as the accent. Seen in: Jeep (https://brandsweets.com/colors/brands/jeep-com), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Rolex (https://brandsweets.com/colors/brands/rolex-com), Instacart (https://brandsweets.com/colors/brands/instacart-com). — https://brandsweets.com/colors/blue
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #1d4e59: 6 real palettes, including Paper & Pine and Dusk, as the supporting colour. Seen in: Paper & Pine (https://brandsweets.com/palettes/minimal#paper-and-pine), Dusk (https://brandsweets.com/palettes/cool#dusk), Open House (https://brandsweets.com/palettes/clean#open-house), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty). — https://brandsweets.com/colors/cadetblue
- **Copper** #b87333 [pool] — Designers have shipped Copper with #1d4e59: 4 real palettes, including Desert Road and Notion's brand system, as the lead colour. Seen in: Desert Road (https://brandsweets.com/palettes/warm#desert-road), Notion (https://brandsweets.com/colors/brands/notion), Dusk (https://brandsweets.com/palettes/cool#dusk), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #1d4e59 in 6 real palettes, including Codecademy's brand system and Frost & Ember, as the accent. Seen in: Codecademy (https://brandsweets.com/colors/brands/codecademy-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember), Marvel (https://brandsweets.com/colors/brands/marvel-com), Dunkin' (https://brandsweets.com/colors/brands/dunkindonuts-com). — https://brandsweets.com/colors/crimson
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #1d4e59: 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): 9.19:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.29:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #2f8092 (4.62:1); AA: background → #b8b8b8 (4.63:1); AAA: text → #3ca2b9 (7.06:1); AAA: background → #e3e3e3 (7.16:1)

## Brands using this color

- **Codecademy** — secondary #2c4c5c (Δ 1.701) — https://brandsweets.com/colors/brands/codecademy-com
- **Gusto** — accent #00535c (Δ 1.863) — https://brandsweets.com/colors/brands/gusto-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/1d4e59-a2b6be-df4e7a-1f252d-e9f1ef?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: "#1d4e59" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.