Color

#643d94

#643d94
hex#643d94
rgbrgb(100, 61, 148)
hslhsl(267, 42%, 41%)
oklchoklch(0.449 0.139 301.7)
Closest name: rebeccapurple (#663399)Relative luminance 0.0818

Colors that go with #643d94

Charcoal, Crimson and Denim lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#6d943d

#3d4194 · #903d94

#94643d · #3d9464

Split-complementary

Open in tool →

#94903d · #41943d

#943d41 · #6d943d · #3d9490

Contrast

#643d94 as textRatioAAAA largeAAAFix
Aaon white
7.96:1passpasspassPasses AAA — no fix needed.
Aaon black
2.64:1failfailfail
  • AA: use #8d63bf as the text (4.67:1)
  • AAA: use #a788ce as the text (7.06:1)
  • AA: or shift the background to #c4c4c4 (4.57:1)
  • AAA: or shift the background to #f2f2f2 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #643d94 as the background.

Brands using this color

Fonts for this mood

#643d94 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #643d94
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #643d94 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/643d94-b39cc4-dfda4e-2c1f2d-e9eaf1?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md