# #663ea3

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

## Values

- Hex: `#663ea3`
- RGB: rgb(102, 62, 163)
- HSL: hsl(264, 45%, 44%)
- OKLCH: oklch(0.464 0.157 298.3)
- Relative luminance: 0.0891
- Nearest named color: rebeccapurple (#663399, Δ 2.749) — https://brandsweets.com/colors/rebeccapurple
- Moods: cool, modern
- Page: https://brandsweets.com/colors/663ea3

## Tints & shades

- Tints (toward white): #7245b5, #8259c0, #906bc7, #a081cf, #ae94d6, #bca6dd, #cdbce6, #dbcfed, #ece5f5, #f9f8fc
- Shades (toward black): #5d3894, #543285, #4a2d76, #412768, #382259, #2e1c4a, #25163b, #1c112c, #130b1e, #09060f

## Harmonies

- Complementary: #7aa33e
- Analogous: #3e48a3, #993ea3
- Triadic: #a3663e, #3ea366
- Split-complementary: #a3993e, #48a33e
- Tetradic: #a33e48, #7aa33e, #3ea399

## Colors that go with #663ea3

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 #663ea3: 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), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #663ea3's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Wayfair (https://brandsweets.com/colors/brands/wayfair-com), Fivetran blue (https://brandsweets.com/colors/brands/fivetran-com), Guinness (https://brandsweets.com/colors/brands/guinness-com), Carrefour (https://brandsweets.com/colors/brands/carrefour-com). — https://brandsweets.com/colors/royalblue
- **Blue** #0000ff [pool] — 4 real palettes, including Zillow's brand system and Pixar's brand system put Blue beside #663ea3, as the lead colour. Seen in: Zillow (https://brandsweets.com/colors/brands/zillow-com), Pixar (https://brandsweets.com/colors/brands/pixar-com), Tesco (https://brandsweets.com/colors/brands/tesco-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #663ea3 in 9 real palettes, including Wells Fargo's brand system and Gemstone, as the lead colour. Seen in: Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Gemstone (https://brandsweets.com/palettes/vivid#gemstone), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Netflix (https://brandsweets.com/colors/brands/netflix). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #663ea3: 9 real palettes, including Linkedin's brand system and Slack's brand system, as the lead colour. Seen in: Linkedin (https://brandsweets.com/colors/brands/linkedin-com), Slack (https://brandsweets.com/colors/brands/slack-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/denim
- **Midnight Blue** #191970 [pool] — 11 real palettes, including Kraken's brand system and Paramount+'s brand system put Midnight Blue beside #663ea3, as the lead colour. Seen in: Kraken (https://brandsweets.com/colors/brands/kraken-com), Paramount+ (https://brandsweets.com/colors/brands/paramountplus-com), Panasonic (https://brandsweets.com/colors/brands/panasonic-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/midnightblue
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #663ea3: 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). — https://brandsweets.com/colors/seagreen
- **Taupe** #483c32 [pool] — Taupe is paired with #663ea3 in 4 real palettes, including Datadog's brand system and Superhuman's brand system, as that palette's text colour. Seen in: Datadog (https://brandsweets.com/colors/brands/datadoghq-com), Superhuman (https://brandsweets.com/colors/brands/superhuman-com), Dusk (https://brandsweets.com/palettes/cool#dusk), Nikon (https://brandsweets.com/colors/brands/nikon-com). — https://brandsweets.com/colors/taupe

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

- On white (#ffffff): 7.55:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.78:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8a64c4 (4.7:1); AA: background → #c9c9c9 (4.56:1); AAA: text → #a689d2 (7.13:1); AAA: background → #f7f7f7 (7.04:1)

## 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/663ea3-b19cc4-dfd34e-2b1f2d-e9eaf1?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: "#663ea3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.