Color

#666ec2

#666ec2
hex#666ec2
rgbrgb(102, 110, 194)
hslhsl(235, 43%, 58%)
oklchoklch(0.571 0.129 277.4)
Closest name: Flood (#6677bb)Relative luminance 0.1787

Colors that go with #666ec2

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 →

#c2ba66

#669cc2 · #8c66c2

#c2666e · #6ec266

Split-complementary

Open in tool →

#c28c66 · #9cc266

#c2669c · #c2ba66 · #66c28c

Contrast

#666ec2 as textRatioAAAA largeAAAFix
Aaon white
4.59:1passpassfail
  • AAA: use #464faf as the text (7.01:1)
Aaon black
4.57:1passpassfail
  • AAA: use #8e94d2 as the text (7.32:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666ec2 as the background.

Brands using this color

Fonts for this mood

#666ec2 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #666ec2
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 #666ec2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666ec2-9e9cc4-df8d4e-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