# #370fa3

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

## Values

- Hex: `#370fa3`
- RGB: rgb(55, 15, 163)
- HSL: hsl(256, 83%, 35%)
- OKLCH: oklch(0.361 0.205 281.1)
- Relative luminance: 0.038
- Nearest named color: Galactic Highway (#3311bb, Δ 4.206) — https://brandsweets.com/colors/galactic-highway
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/370fa3

## Tints & shades

- Tints (toward white): #4012bf, #4b15e0, #5c28eb, #7144ee, #8a65f1, #9f81f3, #b59df6, #cab9f8, #e3dafc, #f8f6fe
- Shades (toward black): #320e95, #2d0d87, #290b79, #240a6b, #1f095d, #19074b, #14063d, #10042f, #0b0321, #060213

## Harmonies

- Complementary: #7ca30f
- Analogous: #0f32a3, #810fa3
- Triadic: #a3370f, #0fa337
- Split-complementary: #a3810f, #32a30f
- Tetradic: #a30f32, #7ca30f, #0fa381

## Colors that go with #370fa3

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

- **Denim** #1560bd [harmony, pool: analogous] — Denim is #370fa3'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), Intel (https://brandsweets.com/colors/brands/intel-com), Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com). — https://brandsweets.com/colors/denim
- **Blue** #0000ff [pool] — 4 real palettes, including Procter & Gamble's brand system and Zillow's brand system put Blue beside #370fa3, 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), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #370fa3: 5 real palettes, including Tide's brand system and Zillow's brand system, as the lead colour. Seen in: Tide (https://brandsweets.com/colors/brands/tide-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #370fa3 in 5 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), Behance (https://brandsweets.com/colors/brands/behance-net), Walgreens (https://brandsweets.com/colors/brands/walgreens-com). — https://brandsweets.com/colors/crimson
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #370fa3: 4 real palettes, including 3M's brand system and Datadog's brand system, as the supporting colour. Seen in: 3M (https://brandsweets.com/colors/brands/3m-com), Datadog (https://brandsweets.com/colors/brands/datadoghq-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), MLB (https://brandsweets.com/colors/brands/mlb-com). — https://brandsweets.com/colors/firebrick
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #370fa3 in 6 real palettes, including Nivea's brand system and Discord's brand system, as the supporting colour. Seen in: Nivea (https://brandsweets.com/colors/brands/nivea-com), Discord (https://brandsweets.com/colors/brands/discord), Nokia (https://brandsweets.com/colors/brands/nokia-com), NHL (https://brandsweets.com/colors/brands/nhl-com). — https://brandsweets.com/colors/royalblue
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #370fa3 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
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #370fa3: 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): 11.93:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.76:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8057ef (4.53:1); AA: background → #a1a1a1 (4.62:1); AAA: text → #a386f4 (7.27:1); AAA: background → #c7c7c7 (7.06:1)

## 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/370fa3-ab9cc4-dfbf4e-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: "#370fa3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.