# #51687b

A color — cool, muted. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#51687b`
- RGB: rgb(81, 104, 123)
- HSL: hsl(207, 21%, 40%)
- OKLCH: oklch(0.506 0.041 243.6)
- Relative luminance: 0.1308
- Nearest named color: Admiral Blue (#50647f, Δ 1.562) — https://brandsweets.com/colors/admiral-blue
- Moods: cool, muted
- Page: https://brandsweets.com/colors/51687b

## Tints & shades

- Tints (toward white): #5d788e, #6b879e, #7a94a8, #8da3b4, #9fb2c1, #b2c1cd, #c4d0d9, #d4dce3, #e6ebef, #f9fafb
- Shades (toward black): #495e6f, #425666, #3a4c59, #344450, #2c3944, #242f38, #1e272e, #161d22, #101519, #080a0c

## Harmonies

- Complementary: #7b6451
- Analogous: #517b79, #51537b
- Triadic: #7b5168, #687b51
- Split-complementary: #7b5153, #7b7951
- Tetradic: #79517b, #7b6451, #537b51

## Colors that go with #51687b

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 #51687b: softer than #000 and cool enough to feel like part of the same palette. Seen in: Campus (https://brandsweets.com/palettes/friendly#campus), Harbour (https://brandsweets.com/palettes/cool#harbour), Gusto (https://brandsweets.com/colors/brands/gusto-com), Pampers (https://brandsweets.com/colors/brands/pampers-com). — https://brandsweets.com/colors/charcoal
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #51687b on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Olive Grove (https://brandsweets.com/palettes/muted#olive-grove). — https://brandsweets.com/colors/sienna
- **Amber** #ffbf00 [pool] — Amber is paired with #51687b in 5 real palettes, including Lemon Squeezy's brand system and McDonald's's brand system, as the lead colour. Seen in: Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Wired (https://brandsweets.com/colors/brands/wired-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 4 real palettes, including Activision's brand system and Warp's brand system put Blue beside #51687b, as the accent. Seen in: Activision (https://brandsweets.com/colors/brands/activision-com), Warp (https://brandsweets.com/colors/brands/warp-dev), Pixar (https://brandsweets.com/colors/brands/pixar-com), Tesco (https://brandsweets.com/colors/brands/tesco-com). — https://brandsweets.com/colors/blue
- **Champagne** #f7e7ce [pool] — 5 real palettes, including Darkroom and BrandSweets's brand system put Champagne beside #51687b, as the surface under it. Seen in: Darkroom (https://brandsweets.com/palettes/muted#darkroom), BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Forest Floor (https://brandsweets.com/palettes/dark#forest-floor), Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar). — https://brandsweets.com/colors/champagne
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #51687b: 6 real palettes, including Fintech Trust and Ink & Paper, as the lead colour. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Ink & Paper (https://brandsweets.com/palettes/minimal#ink-and-paper), Glacier (https://brandsweets.com/palettes/cool#glacier), Hershey's (https://brandsweets.com/colors/brands/hersheys-com). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #51687b: 5 real palettes, including Dusk and Desert Road, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Desert Road (https://brandsweets.com/palettes/warm#desert-road), Riverbed (https://brandsweets.com/palettes/muted#riverbed), Clay & Linen (https://brandsweets.com/palettes/warm#clay-and-linen). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #51687b in 14 real palettes, including Retro Pop and Gemstone, as the lead colour. Seen in: Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Gemstone (https://brandsweets.com/palettes/vivid#gemstone), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Redfin (https://brandsweets.com/colors/brands/redfin-com). — https://brandsweets.com/colors/crimson

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

- On white (#ffffff): 5.81:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #475b6c (7.04:1)
- On black (#000000): 3.62:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #5d788e (4.54:1); AA: background → #e3e3e3 (4.53:1); AAA: text → #8099ac (7.07:1)

## Brands using this color

- **Lufthansa** — secondary #52627c (Δ 1.876) — https://brandsweets.com/colors/brands/lufthansa-com

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/51687b-9cadc4-df4e53-1f212d-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: "#51687b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.