Color

#666cd6

#666cd6
hex#666cd6
rgbrgb(102, 108, 214)
hslhsl(237, 58%, 62%)
oklchoklch(0.579 0.16 277.7)
Closest name: slateblue (#6a5acd)Relative luminance 0.184

Tints & shades

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

Harmonies

Complementary

Open in tool →

#d6d166

#66a4d6 · #9866d6

#d6666c · #6cd666

Split-complementary

Open in tool →

#d69866 · #a4d666

#d666a4 · #d6d166 · #66d698

Contrast

#666cd6 as textRatioAAAA largeAAAFix
Aaon white
4.49:1failpassfail
  • AA: use #6268d5 as the text (4.71:1)
  • AAA: use #3e45cc as the text (7.17:1)
  • AA: or shift the background to #050505 (4.54:1)
Aaon black
4.68:1passpassfail
  • AAA: use #8a8ee0 as the text (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666cd6 as the background.

Brands using this color

Fonts for this mood

#666cd6 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #666cd6
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #666cd6 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666cd6-9f9cc4-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