# #663a8d

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

## Values

- Hex: `#663a8d`
- RGB: rgb(102, 58, 141)
- HSL: hsl(272, 42%, 39%)
- OKLCH: oklch(0.442 0.135 306.1)
- Relative luminance: 0.0777
- Nearest named color: rebeccapurple (#663399, Δ 2.584) — https://brandsweets.com/colors/rebeccapurple
- Moods: cool, modern
- Page: https://brandsweets.com/colors/663a8d

## Tints & shades

- Tints (toward white): #7643a3, #864eb7, #9463bf, #a379c8, #b28fd1, #bfa1d9, #cdb7e1, #dcccea, #ebe2f3, #faf8fc
- Shades (toward black): #5e3582, #542f74, #4c2b69, #42255b, #3a2150, #2f1b41, #271636, #1d1028, #150c1d, #0a060e

## Harmonies

- Complementary: #618d3a
- Analogous: #3c3a8d, #8d3a8a
- Triadic: #8d663a, #3a8d66
- Split-complementary: #8a8d3a, #3a8d3c
- Tetradic: #8d3c3a, #618d3a, #3a8a8d

## Colors that go with #663a8d

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 #663a8d: softer than #000 and cool enough to feel like part of the same palette. Seen in: Hinge (https://brandsweets.com/colors/brands/hinge-co), Harbour (https://brandsweets.com/palettes/cool#harbour), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [pool] — Crimson is paired with #663a8d in 4 real palettes, including Wells Fargo's brand system and Lenovo's brand system, as the lead colour. Seen in: Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Lenovo (https://brandsweets.com/colors/brands/lenovo-com), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Gemstone (https://brandsweets.com/palettes/vivid#gemstone). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #663a8d: 4 real palettes, including Slack's brand system and Hinge's brand system, as the lead colour. Seen in: Slack (https://brandsweets.com/colors/brands/slack-com), Hinge (https://brandsweets.com/colors/brands/hinge-co), HP (https://brandsweets.com/colors/brands/hp-com), Linkedin (https://brandsweets.com/colors/brands/linkedin-com). — https://brandsweets.com/colors/denim
- **Midnight Blue** #191970 [pool] — 5 real palettes, including Kraken's brand system and First Snow put Midnight Blue beside #663a8d, as the lead colour. Seen in: Kraken (https://brandsweets.com/colors/brands/kraken-com), First Snow (https://brandsweets.com/palettes/cool#first-snow), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/midnightblue
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #663a8d in 4 real palettes, including Wayfair's brand system and Fivetran blue's brand system, as the supporting colour. Seen in: Wayfair (https://brandsweets.com/colors/brands/wayfair-com), Fivetran blue (https://brandsweets.com/colors/brands/fivetran-com), Nokia (https://brandsweets.com/colors/brands/nokia-com), Stripe (https://brandsweets.com/colors/brands/stripe). — https://brandsweets.com/colors/royalblue
- **Tomato** #ff6347 [pool] — 6 real palettes, including Golden Hour and FedEx's brand system put Tomato beside #663a8d, as the supporting colour. Seen in: Golden Hour (https://brandsweets.com/palettes/warm#golden-hour), FedEx (https://brandsweets.com/colors/brands/fedex-com), GitLab (https://brandsweets.com/colors/brands/gitlab), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com). — https://brandsweets.com/colors/tomato
- **Dark Olive Green** #556b2f [harmony: complementary] — Dark Olive Green sits directly opposite #663a8d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/darkolivegreen
- **Taupe** #483c32 [pool] — Taupe is paired with #663a8d in 3 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). — https://brandsweets.com/colors/taupe

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

- On white (#ffffff): 8.22:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.55:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #9260be (4.64:1); AA: background → #c2c2c2 (4.61:1); AAA: text → #ad88ce (7.19:1); AAA: background → #ededed (7.02:1)

## Brands using this color

- **Ledger** — secondary #6a3794 (Δ 1.514) — https://brandsweets.com/colors/brands/ledger-com

## 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/663a8d-b69cc4-c5cb62-2d1f2d-eae9f1?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: "#663a8d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.