# #663bc4

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

## Values

- Hex: `#663bc4`
- RGB: rgb(102, 59, 196)
- HSL: hsl(259, 54%, 50%)
- OKLCH: oklch(0.485 0.2 291.5)
- Relative luminance: 0.0994
- Nearest named color: Blurple (#5539cc, Δ 3.371) — https://brandsweets.com/colors/blurple
- Moods: cool, modern
- Page: https://brandsweets.com/colors/663bc4

## Tints & shades

- Tints (toward white): #764eca, #8562d0, #9172d5, #a085db, #b099e1, #bfade6, #cec0ec, #dad0f1, #eae4f7, #f9f7fd
- Shades (toward black): #5c35b1, #5430a1, #4a2a8d, #41267e, #37206a, #2d1a56, #251547, #1b0f33, #120b23, #080510

## Harmonies

- Complementary: #99c43b
- Analogous: #3b54c4, #ab3bc4
- Triadic: #c4663b, #3bc466
- Split-complementary: #c4ab3b, #54c43b
- Tetradic: #c43b54, #99c43b, #3bc4ab

## Colors that go with #663bc4

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 #663bc4: softer than #000 and cool enough to feel like part of the same palette. Seen in: UEFA (https://brandsweets.com/colors/brands/uefa-com), 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). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #663bc4'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), Yahoo (https://brandsweets.com/colors/brands/yahoo-com), Guinness (https://brandsweets.com/colors/brands/guinness-com). — https://brandsweets.com/colors/royalblue
- **Amber** #ffbf00 [pool] — Amber is paired with #663bc4 in 4 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), Walmart (https://brandsweets.com/colors/brands/walmart-com), Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social). — https://brandsweets.com/colors/amber
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #663bc4: 4 real palettes, including Zillow's brand system and Warbyparker's brand system, as the supporting colour. Seen in: Zillow (https://brandsweets.com/colors/brands/zillow-com), Warbyparker (https://brandsweets.com/colors/brands/warbyparker-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), Oreo (https://brandsweets.com/colors/brands/oreo-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #663bc4: 5 real palettes, including Coca-Cola's brand system and Blue Mono, as the supporting colour. Seen in: Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Gopro (https://brandsweets.com/colors/brands/gopro-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #663bc4 in 8 real palettes, including Gemstone and Wells Fargo's brand system, as the accent. Seen in: Gemstone (https://brandsweets.com/palettes/vivid#gemstone), Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Netflix (https://brandsweets.com/colors/brands/netflix), Ulta Beauty (https://brandsweets.com/colors/brands/ulta-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #663bc4: 5 real palettes, including Linkedin's brand system and Unilever's brand system, as the lead colour. Seen in: Linkedin (https://brandsweets.com/colors/brands/linkedin-com), Unilever (https://brandsweets.com/colors/brands/unilever-com), Dairy Queen (https://brandsweets.com/colors/brands/dairyqueen-com), Slack (https://brandsweets.com/colors/brands/slack-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #663bc4: 4 real palettes, including Datadog's brand system and Campbell's's brand system, as the accent. Seen in: Datadog (https://brandsweets.com/colors/brands/datadoghq-com), Campbell's (https://brandsweets.com/colors/brands/campbells-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Nissan (https://brandsweets.com/colors/brands/nissanusa-com). — https://brandsweets.com/colors/firebrick

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

- On white (#ffffff): 7.03:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.99:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8562d0 (4.66:1); AA: background → #cfcfcf (4.51:1); AAA: text → #a389dc (7.17:1); AAA: background → #ffffff (7.03:1)

## Brands using this color

- **Deno** — primary #6639ba (Δ 1.635) — https://brandsweets.com/colors/brands/deno-com
- **Deno** — accent #6639ba (Δ 1.635) — https://brandsweets.com/colors/brands/deno-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/663bc4-ad9cc4-dfc74e-2a1f2d-e9ebf1?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: "#663bc4" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.