# #421fdb

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

## Values

- Hex: `#421fdb`
- RGB: rgb(66, 31, 219)
- HSL: hsl(251, 75%, 49%)
- OKLCH: oklch(0.447 0.254 277.1)
- Relative luminance: 0.0725
- Nearest named color: Busty Blue (#3300cc, Δ 4.639) — https://brandsweets.com/colors/busty-blue
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/421fdb

## Tints & shades

- Tints (toward white): #5232e2, #6548e5, #785ee8, #8a75eb, #9d8bee, #ac9df1, #bfb3f4, #d2c9f7, #e5e0fb, #f7f6fe
- Shades (toward black): #3c1dc9, #3619b3, #3017a1, #2a148a, #241178, #1d0e62, #180b50, #11083a, #0c0628, #050312

## Harmonies

- Complementary: #b8db1f
- Analogous: #1f5bdb, #9f1fdb
- Triadic: #db421f, #1fdb42
- Split-complementary: #db9f1f, #5bdb1f
- Tetradic: #db1f5b, #b8db1f, #1fdb9f

## Colors that go with #421fdb

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 #421fdb: softer than #000 and cool enough to feel like part of the same palette. Seen in: HP (https://brandsweets.com/colors/brands/hp-com), Campus (https://brandsweets.com/palettes/friendly#campus), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Jeep (https://brandsweets.com/colors/brands/jeep-com). — https://brandsweets.com/colors/charcoal
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #421fdb: 9 real palettes, including Unilever's brand system and Zillow's brand system, as the supporting colour. Seen in: Unilever (https://brandsweets.com/colors/brands/unilever-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Oreo (https://brandsweets.com/colors/brands/oreo-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #421fdb: 6 real palettes, including Qualcomm's brand system and Canva's brand system, as the supporting colour. Seen in: Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Canva (https://brandsweets.com/colors/brands/canva-com), Spotify (https://brandsweets.com/colors/brands/spotify), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #421fdb in 6 real palettes, including Behance's brand system and Dunkin''s brand system, as the accent. Seen in: Behance (https://brandsweets.com/colors/brands/behance-net), Dunkin' (https://brandsweets.com/colors/brands/dunkindonuts-com), Tim Hortons (https://brandsweets.com/colors/brands/timhortons-com), Coinbase (https://brandsweets.com/colors/brands/coinbase). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #421fdb: 6 real palettes, including Unilever's brand system and Pixar's brand system, as the accent. Seen in: Unilever (https://brandsweets.com/colors/brands/unilever-com), Pixar (https://brandsweets.com/colors/brands/pixar-com), Intel (https://brandsweets.com/colors/brands/intel-com), Dairy Queen (https://brandsweets.com/colors/brands/dairyqueen-com). — https://brandsweets.com/colors/denim
- **Dodger Blue** #1e90ff [pool] — Designers have shipped Dodger Blue with #421fdb: 7 real palettes, including Cargo's brand system and Readymag's brand system, as the lead colour. Seen in: Cargo (https://brandsweets.com/colors/brands/cargo-site), Readymag (https://brandsweets.com/colors/brands/readymag-com), Samsung (https://brandsweets.com/colors/brands/samsung-com), Unity (https://brandsweets.com/colors/brands/unity-com). — https://brandsweets.com/colors/dodgerblue
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #421fdb: 5 real palettes, including 3M's brand system and MLB's brand system, as the supporting colour. Seen in: 3M (https://brandsweets.com/colors/brands/3m-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com), Nissan (https://brandsweets.com/colors/brands/nissanusa-com). — https://brandsweets.com/colors/firebrick
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #421fdb — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Intel (https://brandsweets.com/colors/brands/intel-com), Kia (https://brandsweets.com/colors/brands/kia-com), Coinbase (https://brandsweets.com/colors/brands/coinbase). — https://brandsweets.com/colors/seagreen

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

- On white (#ffffff): 8.57:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.45:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #785ee8 (4.56:1); AA: background → #bdbdbd (4.56:1); AAA: text → #9987ee (7.05:1); AAA: background → #ebebeb (7.19:1)

## 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/421fdb-a89cc4-dfb34e-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: "#421fdb" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.