# #643cc3

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

## Values

- Hex: `#643cc3`
- RGB: rgb(100, 60, 195)
- HSL: hsl(258, 53%, 50%)
- OKLCH: oklch(0.484 0.198 290.7)
- Relative luminance: 0.0988
- Nearest named color: Blurple (#5539cc, Δ 3.152) — https://brandsweets.com/colors/blurple
- Moods: cool, modern
- Page: https://brandsweets.com/colors/643cc3

## Tints & shades

- Tints (toward white): #744fc9, #8363cf, #9073d4, #9f86da, #af9ae0, #beade6, #cec1ec, #dad0f1, #e9e4f7, #f9f7fd
- Shades (toward black): #5a36b0, #5231a0, #482b8c, #40267d, #362069, #2c1a56, #241646, #1a1033, #120b23, #080510

## Harmonies

- Complementary: #9bc33c
- Analogous: #3c57c3, #a83cc3
- Triadic: #c3643c, #3cc364
- Split-complementary: #c3a83c, #57c33c
- Tetradic: #c33c57, #9bc33c, #3cc3a8

## Colors that go with #643cc3

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 #643cc3: 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 #643cc3's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Fivetran blue (https://brandsweets.com/colors/brands/fivetran-com), Wayfair (https://brandsweets.com/colors/brands/wayfair-com), Guinness (https://brandsweets.com/colors/brands/guinness-com), Yahoo (https://brandsweets.com/colors/brands/yahoo-com). — https://brandsweets.com/colors/royalblue
- **Sea Green** #2e8b57 [harmony, pool: split] — Sea Green is a split-complement of #643cc3: 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), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/seagreen
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #643cc3: 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 #643cc3: 4 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 #643cc3 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
- **Denim** #1560bd [pool] — Designers have shipped Denim with #643cc3: 6 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), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/denim
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #643cc3: 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): 7.06:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.98:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #8363cf (4.65:1); AA: background → #cfcfcf (4.53:1); AAA: text → #a28adb (7.19:1); AAA: background → #ffffff (7.06:1)

## Brands using this color

- **Deno** — primary #6639ba (Δ 1.587) — https://brandsweets.com/colors/brands/deno-com
- **Deno** — accent #6639ba (Δ 1.587) — 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/643cc3-ad9cc4-dfc44e-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: "#643cc3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.