# #21377d

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

## Values

- Hex: `#21377d`
- RGB: rgb(33, 55, 125)
- HSL: hsl(226, 58%, 31%)
- OKLCH: oklch(0.363 0.122 267)
- Relative luminance: 0.0454
- Nearest named color: Deep Space Royal (#223382, Δ 1.379) — https://brandsweets.com/colors/deep-space-royal
- Moods: cool, modern
- Page: https://brandsweets.com/colors/21377d

## Tints & shades

- Tints (toward white): #294399, #2f4db1, #3a5bcb, #5673d2, #728ada, #8a9ee0, #a6b6e7, #c3cdef, #dbe1f5, #f7f8fd
- Shades (toward black): #1e3171, #1c2e69, #19295d, #152351, #132049, #101a3c, #0d1530, #0a1024, #070c1c, #040710

## Harmonies

- Complementary: #7d6821
- Analogous: #21647d, #3a217d
- Triadic: #7d2137, #377d21
- Split-complementary: #7d3a21, #647d21
- Tetradic: #7d2164, #7d6821, #217d3a

## Colors that go with #21377d

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 #21377d: softer than #000 and cool enough to feel like part of the same palette. Seen in: Tumblr (https://brandsweets.com/colors/brands/tumblr-com), CeraVe (https://brandsweets.com/colors/brands/cerave-com), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com), Codecademy (https://brandsweets.com/colors/brands/codecademy-com). — https://brandsweets.com/colors/charcoal
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #21377d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Glacier (https://brandsweets.com/palettes/cool#glacier), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/steelblue
- **Blue** #0000ff [pool] — 5 real palettes, including Alaska Airlines's brand system and Procter & Gamble's brand system put Blue beside #21377d, as the accent. Seen in: Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Tesco (https://brandsweets.com/colors/brands/tesco-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #21377d in 8 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour. Seen in: Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #21377d: 19 real palettes, including Hasbro's brand system and Panasonic's brand system, as the supporting colour. Seen in: Hasbro (https://brandsweets.com/colors/brands/hasbro-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/denim
- **Orange Red** #ff4500 [pool] — Orange Red is paired with #21377d in 5 real palettes, including Tide's brand system and NASA's brand system, as the accent. Seen in: Tide (https://brandsweets.com/colors/brands/tide-com), NASA (https://brandsweets.com/colors/brands/nasa-gov), Tumblr (https://brandsweets.com/colors/brands/tumblr-com), Audi (https://brandsweets.com/colors/brands/audi-com). — https://brandsweets.com/colors/orangered
- **Powder Blue** #b0e0e6 [pool] — Designers have shipped Powder Blue with #21377d: 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), Macaron (https://brandsweets.com/palettes/light#macaron). — https://brandsweets.com/colors/powderblue
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #21377d in 10 real palettes, including Nokia's brand system and Confluent's brand system, as the supporting colour. Seen in: Nokia (https://brandsweets.com/colors/brands/nokia-com), Confluent (https://brandsweets.com/colors/brands/confluent-io), Discord (https://brandsweets.com/colors/brands/discord), Nivea (https://brandsweets.com/colors/brands/nivea-com). — https://brandsweets.com/colors/royalblue

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

- On white (#ffffff): 11.01:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.91:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #526fd1 (4.55:1); AA: background → #a6a6a6 (4.52:1); AAA: text → #7e94dd (7.17:1); AAA: background → #cfcfcf (7.07:1)

## Fonts for this mood

- 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/21377d-9ca1c4-df774e-221f2d-e9eff1?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: "#21377d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.