Color

#665b9a

#665b9a
hex#665b9a
rgbrgb(102, 91, 154)
hslhsl(250, 26%, 48%)
oklchoklch(0.51 0.098 290.5)
Closest name: Passion Flower (#6f5698)Relative luminance 0.1264

Colors that go with #665b9a

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 →

#909a5b

#5b709a · #855b9a

#9a655b · #5b9a65

Split-complementary

Open in tool →

#9a855b · #709a5b

#9a5b70 · #909a5b · #5b9a85

Contrast

#665b9a as textRatioAAAA largeAAAFix
Aaon white
5.95:1passpassfail
  • AAA: use #5b518a as the text (7.03:1)
Aaon black
3.53:1failpassfail
  • AA: use #786eaa as the text (4.61:1)
  • AAA: use #9992bf as the text (7.22:1)
  • AA: or shift the background to #e0e0e0 (4.51:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #665b9a as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

mcpConnect your agent — build around #665b9a
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 #665b9a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/665b9a-a79cc4-dfb14e-281f2d-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