# #381d81

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

## Values

- Hex: `#381d81`
- RGB: rgb(56, 29, 129)
- HSL: hsl(256, 63%, 31%)
- OKLCH: oklch(0.338 0.155 287.3)
- Relative luminance: 0.033
- Nearest named color: Explorer of the Galaxies (#3a1f76, Δ 1.98) — https://brandsweets.com/colors/explorer-of-the-galaxies
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/381d81

## Tints & shades

- Tints (toward white): #44249e, #4f2ab7, #5d33d1, #7450d7, #8c6ede, #9f86e4, #b6a4ea, #cec1f1, #e1daf7, #f8f7fd
- Shades (toward black): #321a74, #2f196c, #291660, #241353, #20114b, #1b0e3e, #160b32, #100825, #0d071d, #070411

## Harmonies

- Complementary: #66811d
- Analogous: #1d3481, #6a1d81
- Triadic: #81381d, #1d8138
- Split-complementary: #816a1d, #34811d
- Tetradic: #811d34, #66811d, #1d816a

## Colors that go with #381d81

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 #381d81'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), Confluent (https://brandsweets.com/colors/brands/confluent-io), Nokia (https://brandsweets.com/colors/brands/nokia-com). — https://brandsweets.com/colors/royalblue
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #381d81: 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), CeraVe (https://brandsweets.com/colors/brands/cerave-com). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [pool] — Crimson is paired with #381d81 in 6 real palettes, including Casper Sleep's brand system and Nintendo's brand system, as the lead colour. Seen in: 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), Pepsi (https://brandsweets.com/colors/brands/pepsi-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #381d81: 4 real palettes, including Bank of America's brand system and Panasonic's brand system, as the accent. Seen in: Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Hasbro (https://brandsweets.com/colors/brands/hasbro-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com). — https://brandsweets.com/colors/denim
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #381d81: 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 #381d81 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), American Eagle (https://brandsweets.com/colors/brands/ae-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com). — https://brandsweets.com/colors/taupe
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #381d81 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 Alaska Airlines's brand system put Blue beside #381d81, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Zillow (https://brandsweets.com/colors/brands/zillow-com). — https://brandsweets.com/colors/blue

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

- On white (#ffffff): 12.64:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.66:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8261db (4.68:1); AA: background → #9c9c9c (4.61:1); AAA: text → #9f86e4 (7:1); AAA: background → #c2c2c2 (7.1:1)

## 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/381d81-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: "#381d81" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.