# #370d63

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

## Values

- Hex: `#370d63`
- RGB: rgb(55, 13, 99)
- HSL: hsl(269, 77%, 22%)
- OKLCH: oklch(0.289 0.136 299.4)
- Relative luminance: 0.02
- Nearest named color: Fabric of Space (#341758, Δ 2.551) — https://brandsweets.com/colors/fabric-of-space
- Moods: cool, vivid, dark, technical, modern, luxury, bold
- Page: https://brandsweets.com/colors/370d63

## Tints & shades

- Tints (toward white): #4b1287, #5c16a7, #701acb, #8126e3, #964ae8, #ab6fec, #be8ef0, #d3b2f5, #e5d2f9, #faf6fe
- Shades (toward black): #320c5a, #2d0b51, #2a0a4d, #250944, #20083b, #1b0632, #160529, #140524, #0f041b, #0a0212

## Harmonies

- Complementary: #3a630d
- Analogous: #0d0e63, #620d63
- Triadic: #63370d, #0d6337
- Split-complementary: #63620d, #0e630d
- Tetradic: #630d0e, #3a630d, #0d6362

## Colors that go with #370d63

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 #370d63: 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), Plaid (https://brandsweets.com/colors/brands/plaid-com), CeraVe (https://brandsweets.com/colors/brands/cerave-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #370d63's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Discord (https://brandsweets.com/colors/brands/discord), Confluent (https://brandsweets.com/colors/brands/confluent-io), Spectrum (https://brandsweets.com/colors/brands/spectrum-com), Telehealth (https://brandsweets.com/palettes/modern#telehealth). — https://brandsweets.com/colors/royalblue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #370d63: 5 real palettes, including Blue Mono and Purina Pro Plan's brand system, as the lead colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com), Glacier (https://brandsweets.com/palettes/cool#glacier), MLB (https://brandsweets.com/colors/brands/mlb-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #370d63 in 5 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour. Seen in: Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #370d63: 10 real palettes, including Bank of America's brand system and Discover's brand system, as the accent. Seen in: Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com), Discover (https://brandsweets.com/colors/brands/discover-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Skechers (https://brandsweets.com/colors/brands/skechers-com). — https://brandsweets.com/colors/denim
- **Powder Blue** #b0e0e6 [pool] — Designers have shipped Powder Blue with #370d63: 5 real palettes, including First Snow and Glacier, as the accent. Seen in: First Snow (https://brandsweets.com/palettes/cool#first-snow), Glacier (https://brandsweets.com/palettes/cool#glacier), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember), Opera (https://brandsweets.com/colors/brands/opera-com). — https://brandsweets.com/colors/powderblue
- **Sky Blue** #87ceeb [pool] — Sky Blue is paired with #370d63 in 4 real palettes, including Boeing's brand system and Coastal, as the supporting colour. Seen in: Boeing (https://brandsweets.com/colors/brands/boeing-com), Coastal (https://brandsweets.com/palettes/cool#coastal), Pastel Pop (https://brandsweets.com/palettes/playful#pastel-pop), Harbour (https://brandsweets.com/palettes/cool#harbour). — https://brandsweets.com/colors/skyblue
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #370d63: 7 real palettes, including FedEx's brand system and Discover's brand system, as the accent. Seen in: FedEx (https://brandsweets.com/colors/brands/fedex-com), Discover (https://brandsweets.com/colors/brands/discover-com), Deep Water (https://brandsweets.com/palettes/dark#deep-water), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/steelblue

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

- On white (#ffffff): 15:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.4:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #994fe8 (4.64:1); AA: background → #8f8f8f (4.64:1); AAA: text → #b37cee (7.03:1); AAA: background → #b3b3b3 (7.15:1)

## Brands using this color

- **MetaMask** — secondary #3d065f (Δ 1.784) — https://brandsweets.com/colors/brands/metamask-io
- **Kraken** — primary #331469 (Δ 1.798) — https://brandsweets.com/colors/brands/kraken-com

## Fonts for this mood

- technical: https://brandsweets.com/fonts/mood/technical
- modern: https://brandsweets.com/fonts/mood/modern
- luxury: https://brandsweets.com/fonts/mood/luxury
- bold: https://brandsweets.com/fonts/mood/bold

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/370d63-b49cc4-cbcb62-2c1f2d-e9e9f1?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: "#370d63" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.