Color

#643f9d

#643f9d
hex#643f9d
rgbrgb(100, 63, 157)
hslhsl(264, 43%, 43%)
oklchoklch(0.459 0.147 298.6)
Closest name: rebeccapurple (#663399)Relative luminance 0.087

Colors that go with #643f9d

Charcoal, Royal Blue and Crimson 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 →

#779d3f

#3f489d · #933f9d

#9d643f · #3f9d64

Split-complementary

Open in tool →

#9d933f · #489d3f

#9d3f48 · #779d3f · #3f9d93

Contrast

#643f9d as textRatioAAAA largeAAAFix
Aaon white
7.66:1passpasspassPasses AAA — no fix needed.
Aaon black
2.74:1failfailfail
  • AA: use #8862c0 as the text (4.56:1)
  • AAA: use #a68ad0 as the text (7.17:1)
  • AA: or shift the background to #c7c7c7 (4.53:1)
  • AAA: or shift the background to #f5f5f5 (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #643f9d as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#643f9d reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #643f9d
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 #643f9d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/643f9d-b19cc4-dfd34e-2b1f2d-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