Color

#665cc7

#665cc7
hex#665cc7
rgbrgb(102, 92, 199)
hslhsl(246, 49%, 57%)
oklchoklch(0.54 0.161 283.8)
Closest name: slateblue (#6a5acd)Relative luminance 0.146

Colors that go with #665cc7

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 →

#bcc75c

#5c87c7 · #9c5cc7

#c7665c · #5cc766

Split-complementary

Open in tool →

#c79c5c · #87c75c

#c75c87 · #bcc75c · #5cc79c

Contrast

#665cc7 as textRatioAAAA largeAAAFix
Aaon white
5.36:1passpassfail
  • AAA: use #5145bf as the text (7.11:1)
Aaon black
3.92:1failpassfail
  • AA: use #7167cb as the text (4.5:1)
  • AAA: use #958dd8 as the text (7.08:1)
  • AA: or shift the background to #ededed (4.58:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #665cc7 as the background.

Brands using this color

Fonts for this mood

#665cc7 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #665cc7
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 #665cc7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/665cc7-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