Color

#665cc1

#665cc1
hex#665cc1
rgbrgb(102, 92, 193)
hslhsl(246, 45%, 56%)
oklchoklch(0.536 0.153 284.5)
Closest name: slateblue (#6a5acd)Relative luminance 0.1433

Colors that go with #665cc1

Charcoal, Sea Green and Amber 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 →

#b7c15c

#5c85c1 · #995cc1

#c1665c · #5cc166

Split-complementary

Open in tool →

#c1995c · #85c15c

#c15c85 · #b7c15c · #5cc199

Contrast

#665cc1 as textRatioAAAA largeAAAFix
Aaon white
5.43:1passpassfail
  • AAA: use #5246b9 as the text (7.15:1)
Aaon black
3.87:1failpassfail
  • AA: use #746bc7 as the text (4.67:1)
  • AAA: use #9790d5 as the text (7.27:1)
  • AA: or shift the background to #ebebeb (4.56:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #665cc1 as the background.

Brands using this color

Fonts for this mood

#665cc1 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #665cc1
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 #665cc1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/665cc1-a59cc4-dfa74e-271f2d-e9ecf1?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