Color

#666b8a

#666b8a
hex#666b8a
rgbrgb(102, 107, 138)
hslhsl(232, 15%, 47%)
oklchoklch(0.535 0.049 277.5)
Closest name: Dark Prince (#6b6c89)Relative luminance 0.1518

Colors that go with #666b8a

Charcoal, Amber and Champagne 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.

Real palettes that use #666b8a

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#8a8566

#667d8a · #73668a

#8a666b · #6b8a66

Split-complementary

Open in tool →

#8a7366 · #7d8a66

#8a667d · #8a8566 · #668a73

Contrast

#666b8a as textRatioAAAA largeAAAFix
Aaon white
5.2:1passpassfail
  • AAA: use #52566f as the text (7.19:1)
Aaon black
4.04:1failpassfail
  • AA: use #6f7495 as the text (4.61:1)
  • AAA: use #9296af as the text (7.2:1)
  • AA: or shift the background to #f0f0f0 (4.57:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666b8a 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 #666b8a
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 #666b8a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666b8a-9c9dc4-df864e-231f2d-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