Color

#643ea3

#643ea3
hex#643ea3
rgbrgb(100, 62, 163)
hslhsl(263, 45%, 44%)
oklchoklch(0.461 0.156 297.2)
Closest name: rebeccapurple (#663399)Relative luminance 0.088

Colors that go with #643ea3

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 →

#7ca33e

#3e49a3 · #973ea3

#a3643e · #3ea364

Split-complementary

Open in tool →

#a3973e · #49a33e

#a33e49 · #7ca33e · #3ea397

Contrast

#643ea3 as textRatioAAAA largeAAAFix
Aaon white
7.61:1passpasspassPasses AAA — no fix needed.
Aaon black
2.76:1failfailfail
  • AA: use #8964c4 as the text (4.68:1)
  • AAA: use #a589d2 as the text (7.11:1)
  • AA: or shift the background to #c7c7c7 (4.5:1)
  • AAA: or shift the background to #f7f7f7 (7.1:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #643ea3 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

#643ea3 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #643ea3
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 #643ea3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/643ea3-b09cc4-dfd04e-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