# #375c81

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

## Values

- Hex: `#375c81`
- RGB: rgb(55, 92, 129)
- HSL: hsl(210, 40%, 36%)
- OKLCH: oklch(0.464 0.074 249.7)
- Relative luminance: 0.1005
- Nearest named color: Deep Indigo (#4c567a, Δ 2.954) — https://brandsweets.com/colors/deep-indigo
- Moods: cool, modern
- Page: https://brandsweets.com/colors/375c81

## Tints & shades

- Tints (toward white): #406b96, #497aab, #5e8cba, #749cc3, #89abcd, #9fbad6, #b4c9df, #cddbea, #e2ebf3, #f8fafc
- Shades (toward black): #325476, #2e4d6b, #28425d, #233b52, #1f3347, #1a2b3d, #152432, #0f1a24, #0b1219, #060a0e

## Harmonies

- Complementary: #815c37
- Analogous: #378181, #373781
- Triadic: #81375c, #5c8137
- Split-complementary: #813737, #818137
- Tetradic: #813781, #815c37, #378137

## Colors that go with #375c81

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

- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #375c81 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 #375c81 in 5 real palettes, including McDonald's's brand system and Lemon Squeezy's brand system, as the lead colour. Seen in: McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Wired (https://brandsweets.com/colors/brands/wired-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 6 real palettes, including Tesco's brand system and Activision's brand system put Blue beside #375c81, 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
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #375c81: 6 real palettes, including Fintech Trust and Unilever's brand system, as the lead colour. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Unilever (https://brandsweets.com/colors/brands/unilever-com), Glacier (https://brandsweets.com/palettes/cool#glacier), Ink & Paper (https://brandsweets.com/palettes/minimal#ink-and-paper). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #375c81 in 16 real palettes, including Costco's brand system and Codecademy's brand system, as the lead colour. Seen in: Costco (https://brandsweets.com/colors/brands/costco-com), Codecademy (https://brandsweets.com/colors/brands/codecademy-com), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com). — https://brandsweets.com/colors/crimson
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #375c81: 5 real palettes, including Fireside and Wendy's's brand system, as the lead colour. Seen in: Fireside (https://brandsweets.com/palettes/dark#fireside), Wendy's (https://brandsweets.com/colors/brands/wendys-com), AT&T (https://brandsweets.com/colors/brands/att-com), Campbell's (https://brandsweets.com/colors/brands/campbells-com). — https://brandsweets.com/colors/firebrick
- **Goldenrod** #daa520 [pool] — Goldenrod shows up next to #375c81 in 5 real palettes, including Open House and Mid-Century, as the accent. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Mid-Century (https://brandsweets.com/palettes/warm#mid-century), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Fireside (https://brandsweets.com/palettes/dark#fireside). — https://brandsweets.com/colors/goldenrod
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #375c81: 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): 6.98:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #36597d (7.29:1)
- On black (#000000): 3.01:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #4878a8 (4.53:1); AA: background → #d1d1d1 (4.57:1); AAA: text → #7099c2 (7.02:1)

## Brands using this color

- **Capital One** — secondary #255f82 (Δ 1.711) — https://brandsweets.com/colors/brands/capitalone-com

## 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/375c81-9cabc4-df514e-1f202d-e9f1f1?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: "#375c81" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.