# #664fc9

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

## Values

- Hex: `#664fc9`
- RGB: rgb(102, 79, 201)
- HSL: hsl(251, 53%, 55%)
- OKLCH: oklch(0.519 0.181 287)
- Relative luminance: 0.1263
- Nearest named color: slateblue (#6a5acd, Δ 2.705) — https://brandsweets.com/colors/slateblue
- Moods: cool, modern
- Page: https://brandsweets.com/colors/664fc9

## Tints & shades

- Tints (toward white): #735fce, #8473d4, #9282d9, #a092dd, #b1a5e3, #beb5e8, #ccc4ed, #dad4f2, #ebe8f8, #f8f7fd
- Shades (toward black): #553cc3, #4c36b0, #44309c, #3b2a89, #332475, #291d5e, #20174a, #181137, #0f0b23, #070510

## Harmonies

- Complementary: #b3c94f
- Analogous: #4f76c9, #a34fc9
- Triadic: #c9664f, #4fc966
- Split-complementary: #c9a34f, #76c94f
- Tetradic: #c94f76, #b3c94f, #4fc9a3

## Colors that go with #664fc9

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 #664fc9: softer than #000 and cool enough to feel like part of the same palette. Seen in: Hinge (https://brandsweets.com/colors/brands/hinge-co), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Starlink (https://brandsweets.com/colors/brands/starlink-com), UEFA (https://brandsweets.com/colors/brands/uefa-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #664fc9: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Netflix (https://brandsweets.com/colors/brands/netflix), Paramount+ (https://brandsweets.com/colors/brands/paramountplus-com), Next.js (https://brandsweets.com/colors/brands/nextjs-org). — https://brandsweets.com/colors/seagreen
- **Amber** #ffbf00 [pool] — Amber is paired with #664fc9 in 6 real palettes, including Warner Bros.'s brand system and Wikipedia's brand system, as the accent. Seen in: Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org), Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), NBA (https://brandsweets.com/colors/brands/nba-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 9 real palettes, including Pixar's brand system and Signal's brand system put Blue beside #664fc9, as the accent. Seen in: Pixar (https://brandsweets.com/colors/brands/pixar-com), Signal (https://brandsweets.com/colors/brands/signal-org), Headspace (https://brandsweets.com/colors/brands/headspace-com), Zillow (https://brandsweets.com/colors/brands/zillow-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #664fc9: 10 real palettes, including Warbyparker's brand system and Unilever's brand system, as the supporting colour. Seen in: Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), NHL (https://brandsweets.com/colors/brands/nhl-com), Nokia (https://brandsweets.com/colors/brands/nokia-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #664fc9: 7 real palettes, including Coca-Cola's brand system and Mastodon hosted on mastodon.social's brand system, as the supporting colour. Seen in: Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), Gopro (https://brandsweets.com/colors/brands/gopro-com), NBA (https://brandsweets.com/colors/brands/nba-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #664fc9 in 15 real palettes, including Marvel's brand system and Netflix's brand system, as the accent. Seen in: Marvel (https://brandsweets.com/colors/brands/marvel-com), Netflix (https://brandsweets.com/colors/brands/netflix), Ulta Beauty (https://brandsweets.com/colors/brands/ulta-com), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #664fc9: 4 real palettes, including Calm's brand system and Kraken's brand system, as the lead colour. Seen in: Calm (https://brandsweets.com/colors/brands/calm-com), Kraken (https://brandsweets.com/colors/brands/kraken-com), Astro (https://brandsweets.com/colors/brands/astro-build), Venmo (https://brandsweets.com/colors/brands/venmo-com). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 5.95:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #5840c4 (7.13:1)
- On black (#000000): 3.53:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #7a67d0 (4.68:1); AA: background → #e0e0e0 (4.51:1); AAA: text → #998adb (7.01:1)

## Brands using this color

- **GitLab** — secondary #6e49cb (Δ 1.756) — https://brandsweets.com/colors/brands/gitlab

## 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/664fc9-a89cc4-dfb34e-281f2d-e9ecf1?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: "#664fc9" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.