# #371fa3

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

## Values

- Hex: `#371fa3`
- RGB: rgb(55, 31, 163)
- HSL: hsl(251, 68%, 38%)
- OKLCH: oklch(0.376 0.194 279.8)
- Relative luminance: 0.0444
- Nearest named color: Depths of Night (#2c319b, Δ 3.439) — https://brandsweets.com/colors/depths-of-night
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/371fa3

## Tints & shades

- Tints (toward white): #4024bc, #4929d6, #5e43db, #745ce0, #8a76e5, #a090ea, #b6a9ef, #ccc3f4, #e2ddf8, #f8f6fd
- Shades (toward black): #331d96, #2d1985, #291778, #231467, #1e115a, #1a0f4d, #140b3c, #10092f, #0a061e, #060311

## Harmonies

- Complementary: #8ba31f
- Analogous: #1f49a3, #791fa3
- Triadic: #a3371f, #1fa337
- Split-complementary: #a3791f, #49a31f
- Tetradic: #a31f49, #8ba31f, #1fa379

## Colors that go with #371fa3

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 #371fa3's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: FedEx (https://brandsweets.com/colors/brands/fedex-com), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/steelblue
- **Blue** #0000ff [pool] — 5 real palettes, including Procter & Gamble's brand system and Zillow's brand system put Blue beside #371fa3, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Pfizer (https://brandsweets.com/colors/brands/pfizer-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #371fa3 in 7 real palettes, including Pepsi's brand system and Walgreens's brand system, as the supporting colour. Seen in: Pepsi (https://brandsweets.com/colors/brands/pepsi-com), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Behance (https://brandsweets.com/colors/brands/behance-net), Casper Sleep (https://brandsweets.com/colors/brands/casper-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #371fa3: 4 real palettes, including Unilever's brand system and Warbyparker's brand system, as the accent. Seen in: Unilever (https://brandsweets.com/colors/brands/unilever-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Intel (https://brandsweets.com/colors/brands/intel-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #371fa3: 4 real palettes, including 3M's brand system and Datadog's brand system, as the supporting colour. Seen in: 3M (https://brandsweets.com/colors/brands/3m-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com). — https://brandsweets.com/colors/firebrick
- **Midnight Blue** #191970 [pool] — 10 real palettes, including Blue Mono and Fintech Trust put Midnight Blue beside #371fa3, as that palette's text colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Kraken (https://brandsweets.com/colors/brands/kraken-com), Air France (https://brandsweets.com/colors/brands/airfrance-com). — https://brandsweets.com/colors/midnightblue
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #371fa3 in 7 real palettes, including Nivea's brand system and Discord's brand system, as the supporting colour. Seen in: Nivea (https://brandsweets.com/colors/brands/nivea-com), Discord (https://brandsweets.com/colors/brands/discord), Nokia (https://brandsweets.com/colors/brands/nokia-com), NHL (https://brandsweets.com/colors/brands/nhl-com). — https://brandsweets.com/colors/royalblue
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #371fa3: 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), Boeing (https://brandsweets.com/colors/brands/boeing-com). — https://brandsweets.com/colors/charcoal

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

- On white (#ffffff): 11.13:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.89:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7860e1 (4.56:1); AA: background → #a6a6a6 (4.57:1); AAA: text → #9c8be9 (7.28:1); AAA: background → #cfcfcf (7.14:1)

## Fonts for this mood

- technical: https://brandsweets.com/fonts/mood/technical
- 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/371fa3-a89cc4-dfb34e-281f2d-e9ecf1?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: "#371fa3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.