# #3f405f

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

## Values

- Hex: `#3f405f`
- RGB: rgb(63, 64, 95)
- HSL: hsl(238, 20%, 31%)
- OKLCH: oklch(0.384 0.053 282.2)
- Relative luminance: 0.0555
- Nearest named color: Bonne Nuit (#3a4866, Δ 2.459) — https://brandsweets.com/colors/bonne-nuit
- Moods: cool, muted
- Page: https://brandsweets.com/colors/3f405f

## Tints & shades

- Tints (toward white): #4e4f74, #5a5b87, #696b9b, #7e80a9, #9495b8, #a6a7c4, #bcbcd2, #d1d2e0, #e3e4ed, #f9f9fb
- Shades (toward black): #393a56, #353650, #2f3046, #29293d, #252537, #1f1f2e, #181925, #12131c, #0e0f15, #08080c

## Harmonies

- Complementary: #5f5e3f
- Analogous: #3f505f, #4e3f5f
- Triadic: #5f3f40, #405f3f
- Split-complementary: #5f4e3f, #505f3f
- Tetradic: #5f3f50, #5f5e3f, #3f5f4e

## Colors that go with #3f405f

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

- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #3f405f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Auth0 (https://brandsweets.com/colors/brands/auth0-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), Glacier (https://brandsweets.com/palettes/cool#glacier), Capital One (https://brandsweets.com/colors/brands/capitalone-com). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #3f405f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Stanley (https://brandsweets.com/colors/brands/stanley1913-com), Gusto (https://brandsweets.com/colors/brands/gusto-com), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), N26 (https://brandsweets.com/colors/brands/n26-com). — https://brandsweets.com/colors/teal
- **Blue** #0000ff [pool] — 10 real palettes, including Alaska Airlines's brand system and Jeep's brand system put Blue beside #3f405f, as the accent. Seen in: Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Jeep (https://brandsweets.com/colors/brands/jeep-com), Dunkin' (https://brandsweets.com/colors/brands/dunkindonuts-com), Minecraft (https://brandsweets.com/colors/brands/minecraft-net). — https://brandsweets.com/colors/blue
- **Blush Pink** #e8b4b8 [pool] — 4 real palettes, including Nursery and Garden Wedding put Blush Pink beside #3f405f, as the lead colour. Seen in: Nursery (https://brandsweets.com/palettes/light#nursery), Garden Wedding (https://brandsweets.com/palettes/light#garden-wedding), Blush (https://brandsweets.com/palettes/light#blush), Rain Garden (https://brandsweets.com/palettes/cool#rain-garden). — https://brandsweets.com/colors/blush-pink
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #3f405f: 5 real palettes, including Paper & Pine and Open House, as the supporting colour. Seen in: Paper & Pine (https://brandsweets.com/palettes/minimal#paper-and-pine), Open House (https://brandsweets.com/palettes/clean#open-house), Dusk (https://brandsweets.com/palettes/cool#dusk), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty). — https://brandsweets.com/colors/cadetblue
- **Copper** #b87333 [pool] — Designers have shipped Copper with #3f405f: 6 real palettes, including Notion's brand system and Bramble. Seen in: Notion (https://brandsweets.com/colors/brands/notion), Bramble (https://brandsweets.com/palettes/muted#bramble), Desert Road (https://brandsweets.com/palettes/warm#desert-road), Dusk (https://brandsweets.com/palettes/cool#dusk). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #3f405f in 10 real palettes, including Codecademy's brand system and Marvel's brand system, as the accent. Seen in: Codecademy (https://brandsweets.com/colors/brands/codecademy-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember), Casper Sleep (https://brandsweets.com/colors/brands/casper-com). — https://brandsweets.com/colors/crimson
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #3f405f: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy. — https://brandsweets.com/colors/whitesmoke

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

- On white (#ffffff): 9.95:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.11:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6f719f (4.54:1); AA: background → #b0b0b0 (4.59:1); AAA: text → #9495b8 (7.25:1); AAA: background → #d9d9d9 (7.05:1)

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/3f405f-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: "#3f405f" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.