# #421f5b

A color — cool, dark, luxury, bold, modern. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#421f5b`
- RGB: rgb(66, 31, 91)
- HSL: hsl(275, 49%, 24%)
- OKLCH: oklch(0.319 0.106 308.4)
- Relative luminance: 0.0289
- Nearest named color: Fading Horizon (#442266, Δ 2.043) — https://brandsweets.com/colors/fading-horizon
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/421f5b

## Tints & shades

- Tints (toward white): #562876, #6c3394, #7f3caf, #9350c3, #a46bcc, #b485d5, #c7a4e0, #d7bee9, #eaddf3, #faf7fc
- Shades (toward black): #3d1d54, #371a4c, #321744, #2c153d, #271235, #21102e, #1c0d26, #160a1e, #110817, #0b050f

## Harmonies

- Complementary: #385b1f
- Analogous: #241f5b, #5b1f56
- Triadic: #5b421f, #1f5b42
- Split-complementary: #565b1f, #1f5b24
- Tetradic: #5b241f, #385b1f, #1f565b

## Colors that go with #421f5b

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

- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #421f5b: softer than #000 and cool enough to feel like part of the same palette. Seen in: Hinge (https://brandsweets.com/colors/brands/hinge-co), Tumblr (https://brandsweets.com/colors/brands/tumblr-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #421f5b: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Asana (https://brandsweets.com/colors/brands/asana-com), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Subaru (https://brandsweets.com/colors/brands/subaru-com), Mushroom (https://brandsweets.com/palettes/neutral#mushroom). — https://brandsweets.com/colors/seagreen
- **Dark Olive Green** #556b2f [harmony, pool: complementary] — Dark Olive Green sits directly opposite #421f5b on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: 7-Eleven (https://brandsweets.com/colors/brands/7-eleven-com), Oatmeal (https://brandsweets.com/palettes/neutral#oatmeal). — https://brandsweets.com/colors/darkolivegreen
- **Blue** #0000ff [pool] — 8 real palettes, including Sketch's brand system and Monzo's brand system put Blue beside #421f5b, as the accent. Seen in: Sketch (https://brandsweets.com/colors/brands/sketch-com), Monzo (https://brandsweets.com/colors/brands/monzo-com), Tim Hortons (https://brandsweets.com/colors/brands/timhortons-com), Minecraft (https://brandsweets.com/colors/brands/minecraft-net). — https://brandsweets.com/colors/blue
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #421f5b: 5 real palettes, including SoFi's brand system and Open House, as the supporting colour. Seen in: SoFi (https://brandsweets.com/colors/brands/sofi-com), Open House (https://brandsweets.com/palettes/clean#open-house), Coastal (https://brandsweets.com/palettes/cool#coastal), Dusk (https://brandsweets.com/palettes/cool#dusk). — https://brandsweets.com/colors/cadetblue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #421f5b: 4 real palettes, including Blue Mono and Purina Pro Plan's brand system, as the lead colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #421f5b: 4 real palettes, including Dusk and Clean Beauty, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty), Notion (https://brandsweets.com/colors/brands/notion), Bramble (https://brandsweets.com/palettes/muted#bramble). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #421f5b in 9 real palettes, including Marvel's brand system and Casper Sleep's brand system, as the accent. Seen in: Marvel (https://brandsweets.com/colors/brands/marvel-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember), Nintendo (https://brandsweets.com/colors/brands/nintendo-com). — https://brandsweets.com/colors/crimson

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

- On white (#ffffff): 13.3:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.58:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #9858c6 (4.55:1); AA: background → #999999 (4.67:1); AAA: text → #b282d4 (7.04:1); AAA: background → #bdbdbd (7.08:1)

## Fonts for this mood

- luxury: https://brandsweets.com/fonts/mood/luxury
- bold: https://brandsweets.com/fonts/mood/bold
- 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/421f5b-b89cc4-c0cb62-2d1f2d-eae9f1?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: "#421f5b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.