# #51557b

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

## Values

- Hex: `#51557b`
- RGB: rgb(81, 85, 123)
- HSL: hsl(234, 21%, 40%)
- OKLCH: oklch(0.462 0.062 279)
- Relative luminance: 0.0968
- Nearest named color: Deep Indigo (#4c567a, Δ 0.808) — https://brandsweets.com/colors/deep-indigo
- Moods: cool, muted
- Page: https://brandsweets.com/colors/51557b

## Tints & shades

- Tints (toward white): #5d628e, #6b709e, #7a7fa8, #8d91b4, #9fa3c1, #b2b5cd, #c4c6d9, #d4d5e3, #e6e7ef, #f9f9fb
- Shades (toward black): #494c6f, #424666, #3a3e59, #343750, #2c2f44, #242638, #1e202e, #161722, #101119, #08080c

## Harmonies

- Complementary: #7b7751
- Analogous: #516a7b, #62517b
- Triadic: #7b5155, #557b51
- Split-complementary: #7b6251, #6a7b51
- Tetradic: #7b516a, #7b7751, #517b62

## Colors that go with #51557b

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 #51557b's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Capital One (https://brandsweets.com/colors/brands/capitalone-com), Auth0 (https://brandsweets.com/colors/brands/auth0-com), American Express (https://brandsweets.com/colors/brands/americanexpress-com), Discover (https://brandsweets.com/colors/brands/discover-com). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #51557b — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Stanley (https://brandsweets.com/colors/brands/stanley1913-com), Gusto (https://brandsweets.com/colors/brands/gusto-com), Clinic (https://brandsweets.com/palettes/clean#clinic), Magazine Ochre (https://brandsweets.com/palettes/editorial#magazine-ochre). — https://brandsweets.com/colors/teal
- **Blue** #0000ff [pool] — 5 real palettes, including Tesco's brand system and CVS's brand system put Blue beside #51557b, as the supporting colour. Seen in: Tesco (https://brandsweets.com/colors/brands/tesco-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Activision (https://brandsweets.com/colors/brands/activision-com), Pixar (https://brandsweets.com/colors/brands/pixar-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #51557b in 14 real palettes, including Wells Fargo's brand system and Codecademy's brand system, as the lead colour. Seen in: Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Codecademy (https://brandsweets.com/colors/brands/codecademy-com), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Costco (https://brandsweets.com/colors/brands/costco-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #51557b: 16 real palettes, including HP's brand system and The New York Times's brand system, as the accent. Seen in: HP (https://brandsweets.com/colors/brands/hp-com), The New York Times (https://brandsweets.com/colors/brands/nytimes-com), Dutch Bros (https://brandsweets.com/colors/brands/dutchbros-com), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #51557b: 5 real palettes, including Fireside and Campbell's's brand system, as the lead colour. Seen in: Fireside (https://brandsweets.com/palettes/dark#fireside), Campbell's (https://brandsweets.com/colors/brands/campbells-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com), AT&T (https://brandsweets.com/colors/brands/att-com). — https://brandsweets.com/colors/firebrick
- **Goldenrod** #daa520 [pool] — Goldenrod shows up next to #51557b in 5 real palettes, including Open House and Mid-Century, as the accent. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Mid-Century (https://brandsweets.com/palettes/warm#mid-century), Fireside (https://brandsweets.com/palettes/dark#fireside), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold). — https://brandsweets.com/colors/goldenrod
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #51557b: 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): 7.15:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.94:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6e73a0 (4.62:1); AA: background → #cfcfcf (4.59:1); AAA: text → #9094b6 (7.1:1); AAA: background → #ffffff (7.15:1)

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/51557b-9d9cc4-df8a4e-241f2d-e9eef1?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: "#51557b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.