# #331d5d

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

## Values

- Hex: `#331d5d`
- RGB: rgb(51, 29, 93)
- HSL: hsl(261, 52%, 24%)
- OKLCH: oklch(0.299 0.109 294.8)
- Relative luminance: 0.0237
- Nearest named color: Fabric of Space (#341758, Δ 1.599) — https://brandsweets.com/colors/fabric-of-space
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/331d5d

## Tints & shades

- Tints (toward white): #432678, #543097, #6338b2, #774dc7, #8c68cf, #a183d8, #b8a2e2, #cdbdea, #e4dcf4, #f9f7fd
- Shades (toward black): #2f1b55, #2b184e, #271646, #22143e, #1e1136, #1a0f2f, #160c27, #110a1f, #0d0717, #090510

## Harmonies

- Complementary: #475d1d
- Analogous: #1d275d, #531d5d
- Triadic: #5d341d, #1d5d34
- Split-complementary: #5d531d, #275d1d
- Tetradic: #5d1d27, #475d1d, #1d5d53

## Colors that go with #331d5d

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 #331d5d: softer than #000 and cool enough to feel like part of the same palette. Seen in: CeraVe (https://brandsweets.com/colors/brands/cerave-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Tumblr (https://brandsweets.com/colors/brands/tumblr-com). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #331d5d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Confluent (https://brandsweets.com/colors/brands/confluent-io), Discord (https://brandsweets.com/colors/brands/discord), Telehealth (https://brandsweets.com/palettes/modern#telehealth), GEICO (https://brandsweets.com/colors/brands/geico-com). — https://brandsweets.com/colors/royalblue
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #331d5d: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Asana (https://brandsweets.com/colors/brands/asana-com), Subaru (https://brandsweets.com/colors/brands/subaru-com), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Mushroom (https://brandsweets.com/palettes/neutral#mushroom). — https://brandsweets.com/colors/seagreen
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #331d5d — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Lufthansa (https://brandsweets.com/colors/brands/lufthansa-com), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Alpine (https://brandsweets.com/palettes/cool#alpine), Stanley (https://brandsweets.com/colors/brands/stanley1913-com). — https://brandsweets.com/colors/teal
- **Amber** #ffbf00 [pool] — Amber is paired with #331d5d in 5 real palettes, including Southwest Airlines's brand system and Beach Hut, as the accent. Seen in: Southwest Airlines (https://brandsweets.com/colors/brands/southwest-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 8 real palettes, including Sketch's brand system and Monzo's brand system put Blue beside #331d5d, 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), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com). — https://brandsweets.com/colors/blue
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #331d5d: 7 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 #331d5d: 7 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), MLB (https://brandsweets.com/colors/brands/mlb-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust). — https://brandsweets.com/colors/cobalt

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

- On white (#ffffff): 14.24:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.47:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8660cd (4.57:1); AA: background → #919191 (4.52:1); AAA: text → #a487d9 (7.05:1); AAA: background → #b8b8b8 (7.18:1)

## Fonts for this mood

- luxury: https://brandsweets.com/fonts/mood/luxury
- bold: https://brandsweets.com/fonts/mood/bold
- 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/331d5d-af9cc4-dfcb4e-2a1f2d-e9eaf1?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: "#331d5d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.