# #331f37

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

## Values

- Hex: `#331f37`
- RGB: rgb(51, 31, 55)
- HSL: hsl(290, 28%, 17%)
- OKLCH: oklch(0.276 0.051 320.8)
- Relative luminance: 0.0196
- Nearest named color: Midnight Velvet (#2a2243, Δ 2.786) — https://brandsweets.com/colors/midnight-velvet
- Moods: cool, muted, dark, luxury, bold
- Page: https://brandsweets.com/colors/331f37

## Tints & shades

- Tints (toward white): #4c2e52, #643d6c, #7c4b86, #945aa0, #a876b2, #b890c1, #c9aacf, #dac4de, #eadeed, #fbf8fb
- Shades (toward black): #301d34, #2a1a2e, #27182a, #241627, #211424, #1b111d, #180f1a, #150d17, #0f0910, #0c070d

## Harmonies

- Complementary: #23371f
- Analogous: #271f37, #371f2f
- Triadic: #37331f, #1f3733
- Split-complementary: #2f371f, #1f3727
- Tetradic: #37271f, #23371f, #1f2f37

## Colors that go with #331f37

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 #331f37: softer than #000 and cool enough to feel like part of the same palette. Seen in: Tide Pool (https://brandsweets.com/palettes/cool#tide-pool), Volkswagen (https://brandsweets.com/colors/brands/vw-com), Boeing (https://brandsweets.com/colors/brands/boeing-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com). — https://brandsweets.com/colors/charcoal
- **Dark Olive Green** #556b2f [harmony, pool: split] — Dark Olive Green is a split-complement of #331f37: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: 7-Eleven (https://brandsweets.com/colors/brands/7-eleven-com), Oatmeal (https://brandsweets.com/palettes/neutral#oatmeal), Clay & Linen (https://brandsweets.com/palettes/warm#clay-and-linen), Cohere (https://brandsweets.com/colors/brands/cohere-com). — https://brandsweets.com/colors/darkolivegreen
- **Sea Green** #2e8b57 [harmony, pool: complementary] — Sea Green sits directly opposite #331f37 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Subaru (https://brandsweets.com/colors/brands/subaru-com), Wellness (https://brandsweets.com/palettes/warm#wellness), Mushroom (https://brandsweets.com/palettes/neutral#mushroom), Asana (https://brandsweets.com/colors/brands/asana-com). — https://brandsweets.com/colors/seagreen
- **Sienna** #a0522d [harmony, pool: triadic] — Sienna completes a triad with #331f37 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove), Harvest (https://brandsweets.com/palettes/warm#harvest), Woodsmoke (https://brandsweets.com/palettes/dark#woodsmoke), BrandSweets (https://brandsweets.com/colors/brands/brandsweets). — https://brandsweets.com/colors/sienna
- **Slate Blue** #6a5acd [harmony, pool: analogous] — Slate Blue is #331f37's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Superhuman (https://brandsweets.com/colors/brands/superhuman-com), GitLab (https://brandsweets.com/colors/brands/gitlab), Indigo SaaS (https://brandsweets.com/palettes/modern#indigo-saas), Sentry (https://brandsweets.com/colors/brands/sentry-io). — https://brandsweets.com/colors/slateblue
- **Teal** #008080 [harmony, pool: split] — Teal is a split-complement of #331f37: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Mid-Century (https://brandsweets.com/palettes/warm#mid-century), Alpine (https://brandsweets.com/palettes/cool#alpine), Gusto (https://brandsweets.com/colors/brands/gusto-com), N26 (https://brandsweets.com/colors/brands/n26-com). — https://brandsweets.com/colors/teal
- **Amber** #ffbf00 [pool] — Amber is paired with #331f37 in 18 real palettes, including McDonald's's brand system and Beach Hut, as the lead colour. Seen in: McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org), Google (https://brandsweets.com/colors/brands/google-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 21 real palettes, including Sketch's brand system and Tim Hortons's brand system put Blue beside #331f37, as the accent. Seen in: Sketch (https://brandsweets.com/colors/brands/sketch-com), Tim Hortons (https://brandsweets.com/colors/brands/timhortons-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), Headspace (https://brandsweets.com/colors/brands/headspace-com). — https://brandsweets.com/colors/blue

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

- On white (#ffffff): 15.09:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.39:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #995fa5 (4.53:1); AA: background → #8f8f8f (4.67:1); AAA: text → #b286bb (7.02:1); AAA: background → #b3b3b3 (7.2:1)

## Brands using this color

- **Sketch** — primary #2c203b (Δ 1.58) — https://brandsweets.com/colors/brands/sketch-com

## Fonts for this mood

- 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/331f37-bf9fc1-a6cb62-2d1f29-ece9f1?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: "#331f37" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.