# #3f428d

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

## Values

- Hex: `#3f428d`
- RGB: rgb(63, 66, 141)
- HSL: hsl(238, 38%, 40%)
- OKLCH: oklch(0.418 0.122 278)
- Relative luminance: 0.0688
- Nearest named color: darkslateblue (#483d8b, Δ 1.793) — https://brandsweets.com/colors/darkslateblue
- Moods: cool, modern
- Page: https://brandsweets.com/colors/3f428d

## Tints & shades

- Tints (toward white): #494ca2, #5659b3, #686abb, #7d7fc5, #9294ce, #a7a9d7, #bcbde1, #cecfe9, #e3e3f2, #f8f8fc
- Shades (toward black): #393b7f, #343674, #2e3066, #292b5b, #23244d, #1c1e3f, #181935, #111227, #0d0d1c, #06070e

## Harmonies

- Complementary: #8d8a3f
- Analogous: #3f698d, #633f8d
- Triadic: #8d3f42, #428d3f
- Split-complementary: #8d633f, #698d3f
- Tetradic: #8d3f69, #8d8a3f, #3f8d63

## Colors that go with #3f428d

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 #3f428d: softer than #000 and cool enough to feel like part of the same palette. Seen in: Harbour (https://brandsweets.com/palettes/cool#harbour), Tumblr (https://brandsweets.com/colors/brands/tumblr-com), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com), Amazon (https://brandsweets.com/colors/brands/amazon-com). — https://brandsweets.com/colors/charcoal
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #3f428d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Glacier (https://brandsweets.com/palettes/cool#glacier), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), American Express (https://brandsweets.com/colors/brands/americanexpress-com). — https://brandsweets.com/colors/steelblue
- **Blue** #0000ff [pool] — 7 real palettes, including CVS's brand system and Tesco's brand system put Blue beside #3f428d, as the supporting colour. Seen in: CVS (https://brandsweets.com/colors/brands/cvs-com), Tesco (https://brandsweets.com/colors/brands/tesco-com), Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com). — https://brandsweets.com/colors/blue
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #3f428d: 5 real palettes, including Blue Mono and Gopro's brand system, as the supporting colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Gopro (https://brandsweets.com/colors/brands/gopro-com), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), Peacock (https://brandsweets.com/colors/brands/peacocktv-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #3f428d in 14 real palettes, including Walgreens's brand system and Wells Fargo's brand system, as the lead colour. Seen in: Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Costco (https://brandsweets.com/colors/brands/costco-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #3f428d: 16 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), General Mills (https://brandsweets.com/colors/brands/generalmills-com), HP (https://brandsweets.com/colors/brands/hp-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #3f428d: 4 real palettes, including Datadog's brand system and MLB's brand system, as the accent. Seen in: Datadog (https://brandsweets.com/colors/brands/datadoghq-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Campbell's (https://brandsweets.com/colors/brands/campbells-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com). — https://brandsweets.com/colors/firebrick
- **Midnight Blue** #191970 [pool] — 19 real palettes, including First Snow and Fintech Trust put Midnight Blue beside #3f428d, as that palette's text colour. Seen in: First Snow (https://brandsweets.com/palettes/cool#first-snow), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/midnightblue

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

- On white (#ffffff): 8.84:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.38:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6b6ebd (4.59:1); AA: background → #bababa (4.56:1); AAA: text → #8e90cc (7.01:1); AAA: background → #e6e6e6 (7.08:1)

## Fonts for this mood

- 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/3f428d-9f9cc4-df944e-251f2d-e9edf1?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: "#3f428d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.