# #643ad9

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

## Values

- Hex: `#643ad9`
- RGB: rgb(100, 58, 217)
- HSL: hsl(256, 68%, 54%)
- OKLCH: oklch(0.5 0.225 287.3)
- Relative luminance: 0.1075
- Nearest named color: Blurple (#5539cc, Δ 3.273) — https://brandsweets.com/colors/blurple
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/643ad9

## Tints & shades

- Tints (toward white): #724bdd, #8360e1, #9072e4, #a187e8, #ae98eb, #bca9ef, #cdbff3, #dad0f6, #ebe5fa, #f8f6fd
- Shades (toward black): #5528d2, #4d24bc, #4420a7, #3b1c92, #32187c, #2a1467, #211051, #180b3c, #100727, #070311

## Harmonies

- Complementary: #afd93a
- Analogous: #3a5fd9, #b43ad9
- Triadic: #d9643a, #3ad964
- Split-complementary: #d9b43a, #5fd93a
- Tetradic: #d93a5f, #afd93a, #3ad9b4

## Colors that go with #643ad9

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 #643ad9: softer than #000 and cool enough to feel like part of the same palette. Seen in: Campus (https://brandsweets.com/palettes/friendly#campus), UEFA (https://brandsweets.com/colors/brands/uefa-com), HP (https://brandsweets.com/colors/brands/hp-com), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #643ad9's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Yahoo (https://brandsweets.com/colors/brands/yahoo-com), Walmart (https://brandsweets.com/colors/brands/walmart-com), Fivetran blue (https://brandsweets.com/colors/brands/fivetran-com), Guinness (https://brandsweets.com/colors/brands/guinness-com). — https://brandsweets.com/colors/royalblue
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #643ad9 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. 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), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/seagreen
- **Amber** #ffbf00 [pool] — Amber is paired with #643ad9 in 5 real palettes, including Mastodon hosted on mastodon.social's brand system and Walmart's brand system, as the accent. Seen in: Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), Walmart (https://brandsweets.com/colors/brands/walmart-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 5 real palettes, including Zillow's brand system and Signal's brand system put Blue beside #643ad9, as the lead colour. Seen in: Zillow (https://brandsweets.com/colors/brands/zillow-com), Signal (https://brandsweets.com/colors/brands/signal-org), Pixar (https://brandsweets.com/colors/brands/pixar-com), Headspace (https://brandsweets.com/colors/brands/headspace-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #643ad9: 7 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), Oreo (https://brandsweets.com/colors/brands/oreo-com), NHL (https://brandsweets.com/colors/brands/nhl-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #643ad9: 7 real palettes, including Qualcomm's brand system and Mastodon hosted on mastodon.social's brand system, as the supporting colour. Seen in: Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), Roblox (https://brandsweets.com/colors/brands/roblox-com), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #643ad9 in 9 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

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

- On white (#ffffff): 6.67:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #5e31d8 (7.22:1)
- On black (#000000): 3.15:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #7f5ce0 (4.51:1); AA: background → #d6d6d6 (4.59:1); AAA: text → #a187e8 (7.15:1)

## 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/643ad9-ab9cc4-dfbf4e-291f2d-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: "#643ad9" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.