# #210b37

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

## Values

- Hex: `#210b37`
- RGB: rgb(33, 11, 55)
- HSL: hsl(270, 67%, 13%)
- OKLCH: oklch(0.213 0.082 302.9)
- Relative luminance: 0.0084
- Nearest named color: Midnight Monarch (#1c0f33, Δ 1.619) — https://brandsweets.com/colors/midnight-monarch
- Moods: cool, vivid, dark, technical, modern, luxury, bold
- Page: https://brandsweets.com/colors/210b37

## Tints & shades

- Tints (toward white): #38135e, #4d1980, #6321a6, #7828c8, #8f44da, #a366e1, #ba8ce8, #cfaeef, #e6d4f7, #faf6fd
- Shades (toward black): #1f0a33, #1c092f, #1a082b, #170826, #170826, #140722, #12061e, #0f051a, #0d0415, #0a0311

## Harmonies

- Complementary: #21370b
- Analogous: #0b0b37, #370b37
- Triadic: #37210b, #0b3721
- Split-complementary: #37370b, #0b370b
- Tetradic: #370b0b, #21370b, #0b3737

## Colors that go with #210b37

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 #210b37: softer than #000 and cool enough to feel like part of the same palette. Seen in: Asana (https://brandsweets.com/colors/brands/asana-com), Volkswagen (https://brandsweets.com/colors/brands/vw-com), Audi (https://brandsweets.com/colors/brands/audi-com), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #210b37's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Penpot (https://brandsweets.com/colors/brands/penpot-app), Slate Workspace (https://brandsweets.com/palettes/minimal#slate-workspace), Cisco (https://brandsweets.com/colors/brands/cisco-com), Telehealth (https://brandsweets.com/palettes/modern#telehealth). — https://brandsweets.com/colors/royalblue
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #210b37: 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), Paramount+ (https://brandsweets.com/colors/brands/paramountplus-com), Intel (https://brandsweets.com/colors/brands/intel-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com). — https://brandsweets.com/colors/seagreen
- **Sienna** #a0522d [harmony, pool: triadic] — Sienna completes a triad with #210b37 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar), Oatly (https://brandsweets.com/colors/brands/oatly-com), Woodsmoke (https://brandsweets.com/palettes/dark#woodsmoke), BrandSweets (https://brandsweets.com/colors/brands/brandsweets). — https://brandsweets.com/colors/sienna
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #210b37 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Clinic (https://brandsweets.com/palettes/clean#clinic), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Lufthansa (https://brandsweets.com/colors/brands/lufthansa-com), Gemstone (https://brandsweets.com/palettes/vivid#gemstone). — https://brandsweets.com/colors/teal
- **Amber** #ffbf00 [pool] — Amber is paired with #210b37 in 18 real palettes, including Southwest Airlines's brand system and Blueprint, as the accent. Seen in: Southwest Airlines (https://brandsweets.com/colors/brands/southwest-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 20 real palettes, including Penpot's brand system and Warp's brand system put Blue beside #210b37, as the supporting colour. Seen in: Penpot (https://brandsweets.com/colors/brands/penpot-app), Warp (https://brandsweets.com/colors/brands/warp-dev), League of Legends (https://brandsweets.com/colors/brands/leagueoflegends-com), Sketch (https://brandsweets.com/colors/brands/sketch-com). — https://brandsweets.com/colors/blue
- **Blue Violet** #8a2be2 [pool] — Blue Violet is paired with #210b37 in 10 real palettes, including Gemstone and Yahoo's brand system, as the supporting colour. Seen in: Gemstone (https://brandsweets.com/palettes/vivid#gemstone), 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). — https://brandsweets.com/colors/blueviolet

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

- On white (#ffffff): 17.98:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.17:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #9955dd (4.7:1); AA: background → #808080 (4.55:1); AAA: text → #b37fe6 (7.1:1); AAA: background → #a3a3a3 (7.13:1)

## 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/210b37-b59cc4-c9cb62-2c1f2d-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: "#210b37" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.