# #210b66

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

## Values

- Hex: `#210b66`
- RGB: rgb(33, 11, 102)
- HSL: hsl(255, 81%, 22%)
- OKLCH: oklch(0.265 0.142 281.8)
- Relative luminance: 0.0152
- Nearest named color: Blackmail (#220066, Δ 1.377) — https://brandsweets.com/colors/blackmail
- Moods: cool, vivid, dark, technical, modern, luxury, bold
- Page: https://brandsweets.com/colors/210b66

## Tints & shades

- Tints (toward white): #2e0f8a, #3812ab, #4416d0, #5321e8, #7046ec, #8c6bef, #a58cf3, #c2b1f7, #dbd1fa, #f8f6fe
- Shades (toward black): #1e0a5c, #1b0953, #1a084e, #170745, #14063c, #110533, #0e042a, #0c0425, #09031c, #060212

## Harmonies

- Complementary: #4f660b
- Analogous: #0b2166, #4f0b66
- Triadic: #66210b, #0b6621
- Split-complementary: #664f0b, #21660b
- Tetradic: #660b21, #4f660b, #0b664f

## Colors that go with #210b66

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 #210b66: softer than #000 and cool enough to feel like part of the same palette. Seen in: Boeing (https://brandsweets.com/colors/brands/boeing-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), CeraVe (https://brandsweets.com/colors/brands/cerave-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com). — https://brandsweets.com/colors/charcoal
- **Denim** #1560bd [harmony, pool: analogous] — Denim is #210b66's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Bank of America (https://brandsweets.com/colors/brands/bankofamerica-com), British Airways (https://brandsweets.com/colors/brands/britishairways-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Skechers (https://brandsweets.com/colors/brands/skechers-com). — https://brandsweets.com/colors/denim
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #210b66: 5 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), Arctic (https://brandsweets.com/palettes/clean#arctic). — https://brandsweets.com/colors/cadetblue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #210b66: 7 real palettes, including Glacier and Blue Mono, as the accent. Seen in: Glacier (https://brandsweets.com/palettes/cool#glacier), 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). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #210b66: 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 #210b66 in 5 real palettes, including Nintendo's brand system and Casper Sleep's brand system, as the supporting colour. Seen in: Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Pepsi (https://brandsweets.com/colors/brands/pepsi-com), Marvel (https://brandsweets.com/colors/brands/marvel-com). — https://brandsweets.com/colors/crimson
- **Powder Blue** #b0e0e6 [pool] — Designers have shipped Powder Blue with #210b66: 4 real palettes, including Glacier and First Snow, as the supporting colour. Seen in: Glacier (https://brandsweets.com/palettes/cool#glacier), First Snow (https://brandsweets.com/palettes/cool#first-snow), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember), Opera (https://brandsweets.com/colors/brands/opera-com). — https://brandsweets.com/colors/powderblue
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #210b66 in 8 real palettes, including Discord's brand system and Spectrum's brand system, as the lead colour. Seen in: Discord (https://brandsweets.com/colors/brands/discord), Spectrum (https://brandsweets.com/colors/brands/spectrum-com), Penpot (https://brandsweets.com/colors/brands/penpot-app), GEICO (https://brandsweets.com/colors/brands/geico-com). — https://brandsweets.com/colors/royalblue

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

- On white (#ffffff): 16.1:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.3:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7e59ee (4.55:1); AA: background → #8a8a8a (4.66:1); AAA: text → #a287f2 (7.28:1); AAA: background → #ababab (7.01:1)

## 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/210b66-ab9cc4-dfbd4e-291f2d-e9ebf1?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: "#210b66" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.