# #377ceb

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

## Values

- Hex: `#377ceb`
- RGB: rgb(55, 124, 235)
- HSL: hsl(217, 82%, 57%)
- OKLCH: oklch(0.602 0.182 259.6)
- Relative luminance: 0.2123
- Nearest named color: Blue Öyster Cult (#5577ee, Δ 2.857) — https://brandsweets.com/colors/blue-oyster-cult
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/377ceb

## Tints & shades

- Tints (toward white): #4a89ed, #5d95ef, #6fa1f1, #82adf3, #99bcf5, #abc8f7, #bed4f9, #d1e1fa, #e3edfc, #f6f9fe
- Shades (toward black): #206de9, #155fd5, #1355be, #114aa7, #0e4090, #0b3474, #09295d, #071f46, #04132a, #020813

## Harmonies

- Complementary: #eba637
- Analogous: #37d6eb, #4c37eb
- Triadic: #eb377c, #7ceb37
- Split-complementary: #eb4c37, #d6eb37
- Tetradic: #eb37d6, #eba637, #37eb4c

## Colors that go with #377ceb

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 #377ceb: softer than #000 and cool enough to feel like part of the same palette. Seen in: Disney (https://brandsweets.com/colors/brands/disney-com), Docker (https://brandsweets.com/colors/brands/docker-com), Zoom (https://brandsweets.com/colors/brands/zoom-us), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [harmony, pool: triadic] — Crimson completes a triad with #377ceb — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Pizza Hut (https://brandsweets.com/colors/brands/pizzahut-com), Behance (https://brandsweets.com/colors/brands/behance-net), Foot Locker (https://brandsweets.com/colors/brands/footlocker-com), NASCAR (https://brandsweets.com/colors/brands/nascar-com). — https://brandsweets.com/colors/crimson
- **Copper** #b87333 [harmony, pool: complementary] — Copper sits directly opposite #377ceb on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Notion (https://brandsweets.com/colors/brands/notion). — https://brandsweets.com/colors/copper
- **Amber** #ffbf00 [pool] — Amber is paired with #377ceb in 12 real palettes, including Google's brand system and Walmart's brand system, as the accent. Seen in: Google (https://brandsweets.com/colors/brands/google-com), Walmart (https://brandsweets.com/colors/brands/walmart-com), Heatwave (https://brandsweets.com/palettes/warm#heatwave), NBA (https://brandsweets.com/colors/brands/nba-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 14 real palettes, including Readymag's brand system and Cargo's brand system put Blue beside #377ceb, as the supporting colour. Seen in: Readymag (https://brandsweets.com/colors/brands/readymag-com), Cargo (https://brandsweets.com/colors/brands/cargo-site), Samsung (https://brandsweets.com/colors/brands/samsung-com), Penpot (https://brandsweets.com/colors/brands/penpot-app). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #377ceb: 11 real palettes, including Carrefour's brand system and Behance's brand system, as the accent. Seen in: Carrefour (https://brandsweets.com/colors/brands/carrefour-com), Behance (https://brandsweets.com/colors/brands/behance-net), Nokia (https://brandsweets.com/colors/brands/nokia-com), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/cobalt
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #377ceb: 9 real palettes, including Patreon's brand system and Venmo's brand system, as the supporting colour. Seen in: Patreon (https://brandsweets.com/colors/brands/patreon-com), Venmo (https://brandsweets.com/colors/brands/venmo-com), Elastic (https://brandsweets.com/colors/brands/elastic-co), Astro (https://brandsweets.com/colors/brands/astro-build). — https://brandsweets.com/colors/deepskyblue
- **Denim** #1560bd [pool] — Designers have shipped Denim with #377ceb: 18 real palettes, including Guinness's brand system and Coursera's brand system, as the accent. Seen in: Guinness (https://brandsweets.com/colors/brands/guinness-com), Coursera (https://brandsweets.com/colors/brands/coursera-org), Motorola (https://brandsweets.com/colors/brands/motorola-com), Fivetran blue (https://brandsweets.com/colors/brands/fivetran-com). — https://brandsweets.com/colors/denim

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

- On white (#ffffff): 4:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #2570e9 (4.59:1); AA: background → #141414 (4.6:1); AAA: text → #1252ba (7.14:1)
- On black (#000000): 5.25:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #5d95ef (7.01:1)

## Fonts for this mood

- technical: https://brandsweets.com/fonts/mood/technical
- 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/377ceb-9ca7c4-df624e-201f2d-e9f0f1?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: "#377ceb" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.