# #37378b

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

## Values

- Hex: `#37378b`
- RGB: rgb(55, 55, 139)
- HSL: hsl(240, 43%, 38%)
- OKLCH: oklch(0.389 0.136 278)
- Relative luminance: 0.0541
- Nearest named color: Bluebell (#333399, Δ 2.615) — https://brandsweets.com/colors/bluebell
- Moods: cool, modern
- Page: https://brandsweets.com/colors/37378b

## Tints & shades

- Tints (toward white): #4040a0, #4949b6, #5f5fbf, #7474c8, #8a8ad0, #a0a0d9, #b6b6e2, #cccceb, #e2e2f3, #f8f8fc
- Shades (toward black): #333380, #2d2d71, #292966, #232358, #1f1f4d, #1a1a42, #141433, #101028, #0a0a1a, #06060f

## Harmonies

- Complementary: #8b8b37
- Analogous: #37618b, #61378b
- Triadic: #8b3737, #378b37
- Split-complementary: #8b6137, #618b37
- Tetradic: #8b3761, #8b8b37, #378b61

## Colors that go with #37378b

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 #37378b: softer than #000 and cool enough to feel like part of the same palette. Seen in: dbt Labs (https://brandsweets.com/colors/brands/getdbt-com), Tumblr (https://brandsweets.com/colors/brands/tumblr-com), Harbour (https://brandsweets.com/palettes/cool#harbour), Codecademy (https://brandsweets.com/colors/brands/codecademy-com). — https://brandsweets.com/colors/charcoal
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #37378b's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Glacier (https://brandsweets.com/palettes/cool#glacier), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), FedEx (https://brandsweets.com/colors/brands/fedex-com). — https://brandsweets.com/colors/steelblue
- **Blue** #0000ff [pool] — 5 real palettes, including Procter & Gamble's brand system and CVS's brand system put Blue beside #37378b, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Tesco (https://brandsweets.com/colors/brands/tesco-com), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com). — https://brandsweets.com/colors/blue
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #37378b: 4 real palettes, including Blue Mono and Peacock's brand system, as the supporting colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Peacock (https://brandsweets.com/colors/brands/peacocktv-com), Blizzard (https://brandsweets.com/colors/brands/blizzard-com), Gopro (https://brandsweets.com/colors/brands/gopro-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #37378b in 11 real palettes, including Walgreens's brand system and Casper Sleep's brand system, as the lead colour. Seen in: Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #37378b: 15 real palettes, including Warbyparker's brand system and Unilever's brand system, as the accent. Seen in: Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), Hasbro (https://brandsweets.com/colors/brands/hasbro-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #37378b: 4 real palettes, including Nintendo's brand system and Datadog's brand system, as the accent. Seen in: Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com), MLB (https://brandsweets.com/colors/brands/mlb-com), 3M (https://brandsweets.com/colors/brands/3m-com). — https://brandsweets.com/colors/firebrick
- **Midnight Blue** #191970 [pool] — 14 real palettes, including Fintech Trust and First Snow put Midnight Blue beside #37378b, as that palette's text colour. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), First Snow (https://brandsweets.com/palettes/cool#first-snow), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/midnightblue

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

- On white (#ffffff): 10.09:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.08:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6d6dc5 (4.64:1); AA: background → #b0b0b0 (4.65:1); AAA: text → #9292d3 (7.27:1); AAA: background → #d9d9d9 (7.15:1)

## Fonts for this mood

- 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/37378b-a19cc4-df994e-251f2d-e9edf1?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: "#37378b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.