# #405b91

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

## Values

- Hex: `#405b91`
- RGB: rgb(64, 91, 145)
- HSL: hsl(220, 39%, 41%)
- OKLCH: oklch(0.476 0.094 263.1)
- Relative luminance: 0.1062
- Nearest named color: Dusk (#4e5481, Δ 3.234) — https://brandsweets.com/colors/dusk
- Moods: cool, modern
- Page: https://brandsweets.com/colors/405b91

## Tints & shades

- Tints (toward white): #4968a7, #5575b4, #6a86be, #7f97c7, #95a9d0, #a6b7d8, #bcc8e1, #d1daeb, #e3e8f3, #f8f9fc
- Shades (toward black): #3a5283, #354b79, #2f436a, #283a5c, #243352, #1e2a43, #172135, #111827, #0c121c, #06090e

## Harmonies

- Complementary: #917640
- Analogous: #408491, #4d4091
- Triadic: #91405b, #5b9140
- Split-complementary: #914d40, #849140
- Tetradic: #914084, #917640, #40914d

## Colors that go with #405b91

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 #405b91: 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), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #405b91 — 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), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com). — https://brandsweets.com/colors/seagreen
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #405b91'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), Discover (https://brandsweets.com/colors/brands/discover-com), Auth0 (https://brandsweets.com/colors/brands/auth0-com). — https://brandsweets.com/colors/steelblue
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #405b91 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Dyson (https://brandsweets.com/colors/brands/dyson-com). — https://brandsweets.com/colors/sienna
- **Amber** #ffbf00 [pool] — Amber is paired with #405b91 in 6 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 Activision's brand system put Blue beside #405b91, as the supporting colour. Seen in: Tesco (https://brandsweets.com/colors/brands/tesco-com), Activision (https://brandsweets.com/colors/brands/activision-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Pixar (https://brandsweets.com/colors/brands/pixar-com). — https://brandsweets.com/colors/blue
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #405b91: 4 real palettes, including Coca-Cola's brand system and Gopro's brand system, as the supporting colour. Seen in: Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), Gopro (https://brandsweets.com/colors/brands/gopro-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), NBA (https://brandsweets.com/colors/brands/nba-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #405b91 in 17 real palettes, including Costco's brand system and Walgreens's brand system, as the lead colour. Seen in: Costco (https://brandsweets.com/colors/brands/costco-com), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com). — https://brandsweets.com/colors/crimson

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

- On white (#ffffff): 6.72:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #3d578a (7.17:1)
- On black (#000000): 3.12:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #5575b4 (4.59:1); AA: background → #d4d4d4 (4.54:1); AAA: text → #7f97c7 (7.15:1)

## Curated palettes containing it

- **Dusk** (cool, muted, elegant) — #4b5d8a, #8b97b3, #c07a4e, #eef0f4, #1f2430 — Slate blue with a copper accent — calm, professional, slightly editorial; suits consultancies and journals. — tool: https://brandsweets.com/palettes/new/4b5d8a-8b97b3-c07a4e-eef0f4-1f2430 — collection: https://brandsweets.com/palettes/cool

## 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/405b91-9ca5c4-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: "#405b91" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.