# #421fa3

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

## Values

- Hex: `#421fa3`
- RGB: rgb(66, 31, 163)
- HSL: hsl(256, 68%, 38%)
- OKLCH: oklch(0.385 0.192 285.1)
- Relative luminance: 0.0478
- Nearest named color: Bluebell (#333399, Δ 4.214) — https://brandsweets.com/colors/bluebell
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/421fa3

## Tints & shades

- Tints (toward white): #4d24bc, #5729d6, #6b43db, #7f5ce0, #9476e5, #a890ea, #bca9ef, #d0c3f4, #e4ddf8, #f8f6fd
- Shades (toward black): #3d1d96, #361985, #311778, #2a1467, #25115a, #1f0f4d, #180b3c, #13092f, #0c061e, #070311

## Harmonies

- Complementary: #80a31f
- Analogous: #1f3ea3, #841fa3
- Triadic: #a3421f, #1fa342
- Split-complementary: #a3841f, #3ea31f
- Tetradic: #a31f3e, #80a31f, #1fa384

## Colors that go with #421fa3

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 #421fa3's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. 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
- **Blue** #0000ff [pool] — 5 real palettes, including Zillow's brand system and Procter & Gamble's brand system put Blue beside #421fa3, as the lead colour. Seen in: Zillow (https://brandsweets.com/colors/brands/zillow-com), Procter & Gamble (https://brandsweets.com/colors/brands/pg-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 #421fa3 in 5 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), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Behance (https://brandsweets.com/colors/brands/behance-net). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #421fa3: 5 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), Slack (https://brandsweets.com/colors/brands/slack-com). — https://brandsweets.com/colors/denim
- **Midnight Blue** #191970 [pool] — 8 real palettes, including Kraken's brand system and Blue Mono put Midnight Blue beside #421fa3, as the lead colour. Seen in: Kraken (https://brandsweets.com/colors/brands/kraken-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Air France (https://brandsweets.com/colors/brands/airfrance-com). — https://brandsweets.com/colors/midnightblue
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #421fa3: 4 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
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #421fa3 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 #421fa3: 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): 10.73:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.96:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7f5ce0 (4.51:1); AA: background → #a8a8a8 (4.51:1); AAA: text → #a187e8 (7.15:1); AAA: background → #d1d1d1 (7.03:1)

## 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/421fa3-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: "#421fa3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.