# #331d9f

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

## Values

- Hex: `#331d9f`
- RGB: rgb(51, 29, 159)
- HSL: hsl(250, 69%, 37%)
- OKLCH: oklch(0.366 0.192 278.8)
- Relative luminance: 0.0409
- Nearest named color: Depths of Night (#2c319b, Δ 3.503) — https://brandsweets.com/colors/depths-of-night
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/331d9f

## Tints & shades

- Tints (toward white): #3b22b9, #4327d3, #573ddb, #6e57e0, #8875e6, #9e8fea, #b5a9ef, #cbc3f4, #e1ddf9, #f8f6fd
- Shades (toward black): #2f1b93, #291881, #251574, #211367, #1d115a, #170d49, #130b3c, #0f092f, #0a061e, #060311

## Harmonies

- Complementary: #8a9f1d
- Analogous: #1d499f, #741d9f
- Triadic: #9f331d, #1d9f33
- Split-complementary: #9f741d, #499f1d
- Tetradic: #9f1d49, #8a9f1d, #1d9f74

## Colors that go with #331d9f

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 #331d9f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Hershey's (https://brandsweets.com/colors/brands/hersheys-com), FedEx (https://brandsweets.com/colors/brands/fedex-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 Pfizer's brand system put Blue beside #331d9f, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Pfizer (https://brandsweets.com/colors/brands/pfizer-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #331d9f 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), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Behance (https://brandsweets.com/colors/brands/behance-net). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #331d9f: 5 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), Intel (https://brandsweets.com/colors/brands/intel-com), Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #331d9f: 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), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), MLB (https://brandsweets.com/colors/brands/mlb-com). — https://brandsweets.com/colors/firebrick
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #331d9f 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
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #331d9f 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
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #331d9f: 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): 11.56:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.82:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7560e2 (4.53:1); AA: background → #a3a3a3 (4.58:1); AAA: text → #9a8bea (7.26:1); AAA: background → #cccccc (7.2:1)

## 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/331d9f-a79cc4-dfb14e-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: "#331d9f" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.