Color

#666ab7

#666ab7
hex#666ab7
rgbrgb(102, 106, 183)
hslhsl(237, 36%, 56%)
oklchoklch(0.556 0.118 279.6)
Closest name: Loch Ness (#5f6db0)Relative luminance 0.1655

Colors that go with #666ab7

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 →

#b7b366

#6693b7 · #8b66b7

#b7666a · #6ab766

Split-complementary

Open in tool →

#b78b66 · #93b766

#b76693 · #b7b366 · #66b78b

Contrast

#666ab7 as textRatioAAAA largeAAAFix
Aaon white
4.87:1passpassfail
  • AAA: use #4b4fa0 as the text (7.18:1)
Aaon black
4.31:1failpassfail
  • AA: use #6a6eb9 as the text (4.54:1)
  • AAA: use #9093cb as the text (7.22:1)
  • AA: or shift the background to #f7f7f7 (4.55:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666ab7 as the background.

Brands using this color

Fonts for this mood

#666ab7 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #666ab7
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 #666ab7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666ab7-9f9cc4-df924e-251f2d-e9edf1?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