# #370f57

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

## Values

- Hex: `#370f57`
- RGB: rgb(55, 15, 87)
- HSL: hsl(273, 71%, 20%)
- OKLCH: oklch(0.279 0.121 304.8)
- Relative luminance: 0.0184
- Nearest named color: Fabric of Space (#341758, Δ 1.587) — https://brandsweets.com/colors/fabric-of-space
- Moods: cool, vivid, dark, technical, modern, luxury, bold
- Page: https://brandsweets.com/colors/370f57

## Tints & shades

- Tints (toward white): #4c157a, #621b9d, #7520bc, #8b29db, #9e4ce1, #b16fe7, #c492ed, #d4b1f2, #e7d3f8, #faf6fe
- Shades (toward black): #310d4e, #2e0d4a, #290b41, #260a3d, #210934, #1b072c, #190727, #13051f, #10041a, #0b0311

## Harmonies

- Complementary: #2f570f
- Analogous: #120f57, #570f54
- Triadic: #57370f, #0f5737
- Split-complementary: #54570f, #0f5712
- Tetradic: #57120f, #2f570f, #0f5457

## Colors that go with #370f57

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 #370f57: softer than #000 and cool enough to feel like part of the same palette. Seen in: Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Volkswagen (https://brandsweets.com/colors/brands/vw-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), CeraVe (https://brandsweets.com/colors/brands/cerave-com). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #370f57's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Telehealth (https://brandsweets.com/palettes/modern#telehealth), Spectrum (https://brandsweets.com/colors/brands/spectrum-com), Discord (https://brandsweets.com/colors/brands/discord), Penpot (https://brandsweets.com/colors/brands/penpot-app). — https://brandsweets.com/colors/royalblue
- **Blue** #0000ff [pool] — 5 real palettes, including Sketch's brand system and Monzo's brand system put Blue beside #370f57, as the accent. Seen in: Sketch (https://brandsweets.com/colors/brands/sketch-com), Monzo (https://brandsweets.com/colors/brands/monzo-com), Penpot (https://brandsweets.com/colors/brands/penpot-app), Tim Hortons (https://brandsweets.com/colors/brands/timhortons-com). — https://brandsweets.com/colors/blue
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #370f57: 6 real palettes, including SoFi's brand system and Open House, as the supporting colour. Seen in: SoFi (https://brandsweets.com/colors/brands/sofi-com), Open House (https://brandsweets.com/palettes/clean#open-house), Coastal (https://brandsweets.com/palettes/cool#coastal), Dusk (https://brandsweets.com/palettes/cool#dusk). — https://brandsweets.com/colors/cadetblue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #370f57: 7 real palettes, including Blue Mono and MLB's brand system, as the lead colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), MLB (https://brandsweets.com/colors/brands/mlb-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #370f57: 4 real palettes, including Blue Mono and Peacock's brand system, as the supporting colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Peacock (https://brandsweets.com/colors/brands/peacocktv-com), Arctic (https://brandsweets.com/palettes/clean#arctic), Blueprint (https://brandsweets.com/palettes/technical#blueprint). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #370f57 in 8 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
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #370f57: 5 real palettes, including Kraken's brand system and Deep Water, as the accent. Seen in: Kraken (https://brandsweets.com/colors/brands/kraken-com), Deep Water (https://brandsweets.com/palettes/dark#deep-water), Vimeo (https://brandsweets.com/colors/brands/vimeo-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 15.35:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.37:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #9e4ce1 (4.57:1); AA: background → #8c8c8c (4.56:1); AAA: text → #b87ce9 (7.1:1); AAA: background → #b0b0b0 (7.08:1)

## 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/370f57-b79cc4-c4cb62-2d1f2d-eae9f1?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: "#370f57" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.