# #391b8d

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

## Values

- Hex: `#391b8d`
- RGB: rgb(57, 27, 141)
- HSL: hsl(256, 68%, 33%)
- OKLCH: oklch(0.349 0.172 285.4)
- Relative luminance: 0.0358
- Nearest named color: Galactic Civilization (#442288, Δ 2.755) — https://brandsweets.com/colors/galactic-civilization
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/391b8d

## Tints & shades

- Tints (toward white): #4621ab, #5026c5, #6136d9, #754fde, #8d6de3, #a187e8, #b8a5ee, #cdbff3, #e4ddf8, #f8f6fd
- Shades (toward black): #341881, #2f1674, #2a1467, #25115a, #211051, #1c0d45, #170b38, #11082b, #0c061e, #070311

## Harmonies

- Complementary: #6f8d1b
- Analogous: #1b368d, #731b8d
- Triadic: #8d391b, #1b8d39
- Split-complementary: #8d731b, #368d1b
- Tetradic: #8d1b36, #6f8d1b, #1b8d73

## Colors that go with #391b8d

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

- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #391b8d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Discord (https://brandsweets.com/colors/brands/discord), Nivea (https://brandsweets.com/colors/brands/nivea-com), Nokia (https://brandsweets.com/colors/brands/nokia-com), Confluent (https://brandsweets.com/colors/brands/confluent-io). — https://brandsweets.com/colors/royalblue
- **Crimson** #dc143c [pool] — Crimson is paired with #391b8d in 7 real palettes, including Pepsi's brand system and Casper Sleep's brand system, as the supporting colour. Seen in: Pepsi (https://brandsweets.com/colors/brands/pepsi-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Marvel (https://brandsweets.com/colors/brands/marvel-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #391b8d: 5 real palettes, including Bank of America's brand system and Warbyparker's brand system, as the accent. Seen in: Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Hasbro (https://brandsweets.com/colors/brands/hasbro-com). — https://brandsweets.com/colors/denim
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #391b8d: 5 real palettes, including FedEx's brand system and Hershey's's brand system, as the accent. 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
- **Taupe** #483c32 [pool] — Taupe is paired with #391b8d in 4 real palettes, including Gillette's brand system and Boeing's brand system, as the lead colour. Seen in: Gillette (https://brandsweets.com/colors/brands/gillette-com), Boeing (https://brandsweets.com/colors/brands/boeing-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com), American Eagle (https://brandsweets.com/colors/brands/ae-com). — https://brandsweets.com/colors/taupe
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #391b8d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/olive
- **Blue** #0000ff [pool] — 3 real palettes, including Procter & Gamble's brand system and Zillow's brand system put Blue beside #391b8d, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #391b8d: 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): 12.24:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.72:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7f5ce0 (4.51:1); AA: background → #9e9e9e (4.57:1); AAA: text → #a187e8 (7.15:1); AAA: background → #c4c4c4 (7.02:1)

## 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/391b8d-ab9cc4-dfbf4e-291f2d-e9ebf1?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: "#391b8d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.