# #3f508d

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

## Values

- Hex: `#3f508d`
- RGB: rgb(63, 80, 141)
- HSL: hsl(227, 38%, 40%)
- OKLCH: oklch(0.448 0.102 270.1)
- Relative luminance: 0.0872
- Nearest named color: Assassin (#2d4f83, Δ 2.84) — https://brandsweets.com/colors/assassin
- Moods: cool, modern
- Page: https://brandsweets.com/colors/3f508d

## Tints & shades

- Tints (toward white): #495ca2, #566ab3, #687abb, #7d8cc5, #929fce, #a7b2d7, #bcc4e1, #ced4e9, #e3e6f2, #f8f9fc
- Shades (toward black): #39487f, #344274, #2e3a66, #29345b, #232c4d, #1c243f, #181e35, #111627, #0d101c, #06080e

## Harmonies

- Complementary: #8d7c3f
- Analogous: #3f778d, #553f8d
- Triadic: #8d3f50, #508d3f
- Split-complementary: #8d553f, #778d3f
- Tetradic: #8d3f77, #8d7c3f, #3f8d55

## Colors that go with #3f508d

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 #3f508d: softer than #000 and cool enough to feel like part of the same palette. Seen in: Harbour (https://brandsweets.com/palettes/cool#harbour), Amazon (https://brandsweets.com/colors/brands/amazon-com), Hasbro (https://brandsweets.com/colors/brands/hasbro-com), Tumblr (https://brandsweets.com/colors/brands/tumblr-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #3f508d — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: 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), Subaru (https://brandsweets.com/colors/brands/subaru-com). — https://brandsweets.com/colors/seagreen
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #3f508d'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), Glacier (https://brandsweets.com/palettes/cool#glacier), Auth0 (https://brandsweets.com/colors/brands/auth0-com). — https://brandsweets.com/colors/steelblue
- **Amber** #ffbf00 [pool] — Amber is paired with #3f508d in 4 real palettes, including Warner Bros.'s brand system and McDonald's's brand system, as the accent. Seen in: Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-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 #3f508d, 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 #3f508d 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), Target : Expect More. Pay Less. (https://brandsweets.com/colors/brands/target-com). — https://brandsweets.com/colors/crimson
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #3f508d: 6 real palettes, including Campbell's's brand system and AT&T's brand system, as the supporting colour. Seen in: Campbell's (https://brandsweets.com/colors/brands/campbells-com), AT&T (https://brandsweets.com/colors/brands/att-com), Nissan (https://brandsweets.com/colors/brands/nissanusa-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com). — https://brandsweets.com/colors/firebrick
- **Goldenrod** #daa520 [pool] — Goldenrod shows up next to #3f508d in 4 real palettes, including Open House and Sapphire & Gold, as the accent. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Mid-Century (https://brandsweets.com/palettes/warm#mid-century), Disney (https://brandsweets.com/colors/brands/disney-com). — https://brandsweets.com/colors/goldenrod

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

- On white (#ffffff): 7.65:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.74:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #6174b8 (4.7:1); AA: background → #c7c7c7 (4.53:1); AAA: text → #8796c9 (7.24:1); AAA: background → #f5f5f5 (7.02:1)

## 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/3f508d-9ca0c4-df7a4e-221f2d-e9eff1?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: "#3f508d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.