Color

#666db2

#666db2
hex#666db2
rgbrgb(102, 109, 178)
hslhsl(234, 33%, 55%)
oklchoklch(0.559 0.107 278)
Closest name: Loch Ness (#5f6db0)Relative luminance 0.1698

Colors that go with #666db2

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 →

#b2ab66

#6694b2 · #8566b2

#b2666e · #6eb266

Split-complementary

Open in tool →

#b28566 · #94b266

#b26694 · #b2ab66 · #66b285

Contrast

#666db2 as textRatioAAAA largeAAAFix
Aaon white
4.78:1passpassfail
  • AAA: use #4b5395 as the text (7.07:1)
Aaon black
4.4:1failpassfail
  • AA: use #6a71b4 as the text (4.63:1)
  • AAA: use #8f95c7 as the text (7.29:1)
  • AA: or shift the background to #fafafa (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 #666db2 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 #666db2
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 #666db2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666db2-9d9cc4-df8a4e-241f2d-e9eef1?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