# #3f5683

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

## Values

- Hex: `#3f5683`
- RGB: rgb(63, 86, 131)
- HSL: hsl(220, 35%, 38%)
- OKLCH: oklch(0.455 0.079 263)
- Relative luminance: 0.0935
- Nearest named color: Dusk (#4e5481, Δ 2.053) — https://brandsweets.com/colors/dusk
- Moods: cool, modern
- Page: https://brandsweets.com/colors/3f5683

## Tints & shades

- Tints (toward white): #496397, #5371ac, #6882b6, #7c93c0, #91a4ca, #a5b5d4, #bac6de, #cfd7e8, #e3e8f2, #f8f9fc
- Shades (toward black): #3a4f78, #33466b, #2e3f60, #283653, #232f48, #1e293e, #172030, #121926, #0c1018, #07090e

## Harmonies

- Complementary: #836c3f
- Analogous: #3f7883, #4a3f83
- Triadic: #833f56, #56833f
- Split-complementary: #834a3f, #78833f
- Tetradic: #833f78, #836c3f, #3f834a

## Colors that go with #3f5683

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

- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #3f5683 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Subaru (https://brandsweets.com/colors/brands/subaru-com), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Netflix (https://brandsweets.com/colors/brands/netflix), Paramount+ (https://brandsweets.com/colors/brands/paramountplus-com). — https://brandsweets.com/colors/seagreen
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #3f5683's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Capital One (https://brandsweets.com/colors/brands/capitalone-com), American Express (https://brandsweets.com/colors/brands/americanexpress-com), Auth0 (https://brandsweets.com/colors/brands/auth0-com), Discover (https://brandsweets.com/colors/brands/discover-com). — https://brandsweets.com/colors/steelblue
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #3f5683 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Dyson (https://brandsweets.com/colors/brands/dyson-com). — https://brandsweets.com/colors/sienna
- **Amber** #ffbf00 [pool] — Amber is paired with #3f5683 in 4 real palettes, including McDonald's's brand system and Warner Bros.'s brand system, as the lead colour. Seen in: McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 6 real palettes, including Tesco's brand system and CVS's brand system put Blue beside #3f5683, as the supporting colour. Seen in: Tesco (https://brandsweets.com/colors/brands/tesco-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Activision (https://brandsweets.com/colors/brands/activision-com), Pixar (https://brandsweets.com/colors/brands/pixar-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #3f5683 in 14 real palettes, including Walgreens's brand system and Costco's brand system, as the lead colour. Seen in: Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Costco (https://brandsweets.com/colors/brands/costco-com), Codecademy (https://brandsweets.com/colors/brands/codecademy-com), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com). — https://brandsweets.com/colors/crimson
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #3f5683: 6 real palettes, including Campbell's's brand system and Fireside, as the supporting colour. Seen in: Campbell's (https://brandsweets.com/colors/brands/campbells-com), Fireside (https://brandsweets.com/palettes/dark#fireside), AT&T (https://brandsweets.com/colors/brands/att-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com). — https://brandsweets.com/colors/firebrick
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #3f5683: 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): 7.32:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.87:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #5a76af (4.65:1); AA: background → #cccccc (4.56:1); AAA: text → #8096c2 (7.06:1); AAA: background → #fafafa (7.01:1)

## Curated palettes containing it

- **Harbour** (ocean, cool, muted, editorial) — #3d5a80, #98c1d9, #ee6c4d, #f7f9fb, #293241 — Steel blue and haze with a buoy orange on a pale grey — the maritime palette every port town uses for a reason. — tool: https://brandsweets.com/palettes/new/3d5a80-98c1d9-ee6c4d-f7f9fb-293241 — collection: https://brandsweets.com/palettes/ocean

## 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/3f5683-9ca5c4-df694e-211f2d-e9f0f1?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: "#3f5683" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.