Color

#663a8d

#663a8d
hex#663a8d
rgbrgb(102, 58, 141)
hslhsl(272, 42%, 39%)
oklchoklch(0.442 0.135 306.1)
Closest name: rebeccapurple (#663399)Relative luminance 0.0777

Colors that go with #663a8d

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 →

#618d3a

#3c3a8d · #8d3a8a

#8d663a · #3a8d66

Split-complementary

Open in tool →

#8a8d3a · #3a8d3c

#8d3c3a · #618d3a · #3a8a8d

Contrast

#663a8d as textRatioAAAA largeAAAFix
Aaon white
8.22:1passpasspassPasses AAA — no fix needed.
Aaon black
2.55:1failfailfail
  • AA: use #9260be as the text (4.64:1)
  • AAA: use #ad88ce as the text (7.19:1)
  • AA: or shift the background to #c2c2c2 (4.61:1)
  • AAA: or shift the background to #ededed (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #663a8d as the background.

Brands using this color

Fonts for this mood

#663a8d reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #663a8d
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 #663a8d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/663a8d-b69cc4-c5cb62-2d1f2d-eae9f1?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