# #370a9e

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

## Values

- Hex: `#370a9e`
- RGB: rgb(55, 10, 158)
- HSL: hsl(258, 88%, 33%)
- OKLCH: oklch(0.353 0.202 282.3)
- Relative luminance: 0.035
- Nearest named color: Dramatic Blue (#240093, Δ 4.337) — https://brandsweets.com/colors/dramatic-blue
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/370a9e

## Tints & shades

- Tints (toward white): #420cc0, #4c0edd, #5d1ef1, #723af2, #8a5cf5, #9e79f6, #b79af9, #cbb7fa, #e3d9fd, #f8f5fe
- Shades (toward black): #320990, #2d0881, #280773, #230665, #1f065b, #1a054d, #15043e, #110330, #0c0222, #070113

## Harmonies

- Complementary: #729e0a
- Analogous: #0a289e, #810a9e
- Triadic: #9e370a, #0a9e37
- Split-complementary: #9e810a, #289e0a
- Tetradic: #9e0a28, #729e0a, #0a9e81

## Colors that go with #370a9e

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

- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #370a9e: 5 real palettes, including Tide's brand system and Purina Pro Plan's brand system, as the lead colour. Seen in: Tide (https://brandsweets.com/colors/brands/tide-com), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Unilever (https://brandsweets.com/colors/brands/unilever-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #370a9e in 6 real palettes, including Pepsi's brand system and Casper Sleep's brand system, as the supporting colour. Seen in: Pepsi (https://brandsweets.com/colors/brands/pepsi-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Behance (https://brandsweets.com/colors/brands/behance-net). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [harmony, pool: analogous] — Denim is #370a9e's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Unilever (https://brandsweets.com/colors/brands/unilever-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com). — https://brandsweets.com/colors/denim
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #370a9e in 5 real palettes, including Discord's brand system and Nivea's brand system, as the lead colour. Seen in: Discord (https://brandsweets.com/colors/brands/discord), Nivea (https://brandsweets.com/colors/brands/nivea-com), Nokia (https://brandsweets.com/colors/brands/nokia-com), NHL (https://brandsweets.com/colors/brands/nhl-com). — https://brandsweets.com/colors/royalblue
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #370a9e: 4 real palettes, including FedEx's brand system and Hershey's's brand system, as the accent. Seen in: FedEx (https://brandsweets.com/colors/brands/fedex-com), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/steelblue
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #370a9e on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/olive
- **Blue** #0000ff [pool] — 3 real palettes, including Procter & Gamble's brand system and Zillow's brand system put Blue beside #370a9e, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Pfizer (https://brandsweets.com/colors/brands/pfizer-com). — https://brandsweets.com/colors/blue
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #370a9e: softer than #000 and cool enough to feel like part of the same palette. Seen in: dbt Labs (https://brandsweets.com/colors/brands/getdbt-com), Boeing (https://brandsweets.com/colors/brands/boeing-com). — https://brandsweets.com/colors/charcoal

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

- On white (#ffffff): 12.36:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.7:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8657f4 (4.68:1); AA: background → #9c9c9c (4.5:1); AAA: text → #a582f7 (7.14:1); AAA: background → #c4c4c4 (7.08:1)

## Brands using this color

- **dbt Labs** — accent #3d189a (Δ 1.996) — https://brandsweets.com/colors/brands/getdbt-com

## Fonts for this mood

- technical: https://brandsweets.com/fonts/mood/technical
- 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/370a9e-ad9cc4-dfc44e-291f2d-e9ebf1?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: "#370a9e" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.