# #421d8b

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

## Values

- Hex: `#421d8b`
- RGB: rgb(66, 29, 139)
- HSL: hsl(260, 65%, 33%)
- OKLCH: oklch(0.359 0.167 290.7)
- Relative luminance: 0.039
- Nearest named color: Galactic Civilization (#442288, Δ 1.095) — https://brandsweets.com/colors/galactic-civilization
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/421d8b

## Tints & shades

- Tints (toward white): #5024a8, #5c29c2, #6d39d5, #8052da, #9670e1, #a889e6, #bea7ec, #d0c0f2, #e6ddf8, #f9f7fd
- Shades (toward black): #3c1b7e, #361872, #301565, #2a1358, #261150, #200e43, #1a0c37, #14092a, #0e061d, #080411

## Harmonies

- Complementary: #668b1d
- Analogous: #1d308b, #791d8b
- Triadic: #8b421d, #1d8b42
- Split-complementary: #8b791d, #308b1d
- Tetradic: #8b1d30, #668b1d, #1d8b79

## Colors that go with #421d8b

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 #421d8b'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
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #421d8b: 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), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [pool] — Crimson is paired with #421d8b in 6 real palettes, including Casper Sleep's brand system and Pepsi's brand system, as the lead colour. Seen in: Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Pepsi (https://brandsweets.com/colors/brands/pepsi-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #421d8b: 7 real palettes, including Slack's brand system and Warbyparker's brand system, as the lead colour. Seen in: Slack (https://brandsweets.com/colors/brands/slack-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com). — https://brandsweets.com/colors/denim
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #421d8b: 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
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #421d8b 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 Zillow's brand system and Procter & Gamble's brand system put Blue beside #421d8b, as the lead colour. Seen in: Zillow (https://brandsweets.com/colors/brands/zillow-com), Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #421d8b: 3 real palettes, including Purina Pro Plan's brand system and Zillow's brand system, as the accent. Seen in: Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Unilever (https://brandsweets.com/colors/brands/unilever-com). — https://brandsweets.com/colors/cobalt

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

- On white (#ffffff): 11.8:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.78:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #865bdc (4.54:1); AA: background → #a1a1a1 (4.57:1); AAA: text → #a585e5 (7.09:1); AAA: background → #c9c9c9 (7.12:1)

## 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/421d8b-ae9cc4-dfc94e-2a1f2d-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: "#421d8b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.