# #031d21

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

## Values

- Hex: `#031d21`
- RGB: rgb(3, 29, 33)
- HSL: hsl(188, 83%, 7%)
- OKLCH: oklch(0.213 0.033 208.9)
- Relative luminance: 0.0101
- Nearest named color: Black Stallion (#0e191c, Δ 1.839) — https://brandsweets.com/colors/black-stallion
- Moods: cool, vivid, dark, technical, modern, luxury, bold
- Page: https://brandsweets.com/colors/031d21

## Tints & shades

- Tints (toward white): #07424b, #0b6775, #0f8b9f, #13b0c9, #24d0eb, #4ed9ef, #78e2f2, #a2ebf6, #ccf4fa, #f6fdfe
- Shades (toward black): #031d21, #03191c, #03191c, #03191c, #03191c, #021517, #021517, #021517, #021013, #021013

## Harmonies

- Complementary: #210703
- Analogous: #032116, #030e21
- Triadic: #21031d, #1d2103
- Split-complementary: #21030e, #211603
- Tetradic: #160321, #210703, #0e2103

## Colors that go with #031d21

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 #031d21: softer than #000 and cool enough to feel like part of the same palette. Seen in: Vimeo (https://brandsweets.com/colors/brands/vimeo-com), Asana (https://brandsweets.com/colors/brands/asana-com), Audi (https://brandsweets.com/colors/brands/audi-com), Puma (https://brandsweets.com/colors/brands/puma-com). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [harmony, pool: complementary] — Crimson sits directly opposite #031d21 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Chase (https://brandsweets.com/colors/brands/chase-com), Huawei (https://brandsweets.com/colors/brands/huawei-com), Formula 1 (https://brandsweets.com/colors/brands/formula1-com), Diner (https://brandsweets.com/palettes/vivid#diner). — https://brandsweets.com/colors/crimson
- **Sienna** #a0522d [harmony, pool: split] — Sienna is a split-complement of #031d21: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Oatly (https://brandsweets.com/colors/brands/oatly-com), Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar), Woodsmoke (https://brandsweets.com/palettes/dark#woodsmoke), BrandSweets (https://brandsweets.com/colors/brands/brandsweets). — https://brandsweets.com/colors/sienna
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #031d21's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Launch Orange (https://brandsweets.com/palettes/bold#launch-orange), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), American Express (https://brandsweets.com/colors/brands/americanexpress-com), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: analogous] — Teal is #031d21's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Perplexity (https://brandsweets.com/colors/brands/perplexity), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), N26 (https://brandsweets.com/colors/brands/n26-com), Clinic (https://brandsweets.com/palettes/clean#clinic). — https://brandsweets.com/colors/teal
- **Amber** #ffbf00 [pool] — Amber is paired with #031d21 in 18 real palettes, including Warner Bros.'s brand system and Blueprint, as the accent. Seen in: Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint), Google (https://brandsweets.com/colors/brands/google-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 24 real palettes, including Monzo's brand system and MongoDB's brand system put Blue beside #031d21, as the accent. Seen in: Monzo (https://brandsweets.com/colors/brands/monzo-com), MongoDB (https://brandsweets.com/colors/brands/mongodb-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Kia (https://brandsweets.com/colors/brands/kia-com). — https://brandsweets.com/colors/blue
- **Blue Violet** #8a2be2 [pool] — Blue Violet is paired with #031d21 in 10 real palettes, including Yahoo's brand system and ClickUp's brand system, as the supporting colour. Seen in: Yahoo (https://brandsweets.com/colors/brands/yahoo-com), ClickUp (https://brandsweets.com/colors/brands/clickup-com), Prepare your taste buds... (https://brandsweets.com/colors/brands/grubhub-com), Klarna US (https://brandsweets.com/colors/brands/klarna-com). — https://brandsweets.com/colors/blueviolet

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

- On white (#ffffff): 17.48:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.2:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #0e8395 (4.7:1); AA: background → #828282 (4.55:1); AAA: text → #11a4bb (7.05:1); AAA: background → #a6a6a6 (7.18:1)

## 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/031d21-a2b7be-df4e81-1f252d-e9f1ee?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: "#031d21" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.