Color

#643cb4

#643cb4
hex#643cb4
rgbrgb(100, 60, 180)
hslhsl(260, 50%, 47%)
oklchoklch(0.472 0.18 293.6)
Closest name: rebeccapurple (#663399)Relative luminance 0.0924

Colors that go with #643cb4

Charcoal, Royal Blue and Sea Green 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 →

#8cb43c

#3c50b4 · #a03cb4

#b4643c · #3cb464

Split-complementary

Open in tool →

#b4a03c · #50b43c

#b43c50 · #8cb43c · #3cb4a0

Contrast

#643cb4 as textRatioAAAA largeAAAFix
Aaon white
7.38:1passpasspassPasses AAA — no fix needed.
Aaon black
2.85:1failfailfail
  • AA: use #8562cb as the text (4.61:1)
  • AAA: use #a388d7 as the text (7.06:1)
  • AA: or shift the background to #cccccc (4.59:1)
  • AAA: or shift the background to #fafafa (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #643cb4 as the background.

Brands using this color

Fonts for this mood

#643cb4 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #643cb4
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 #643cb4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/643cb4-ae9cc4-dfc94e-2a1f2d-e9ebf1?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