Color

#666eeb

#666eeb
hex#666eeb
rgbrgb(102, 110, 235)
hslhsl(236, 77%, 66%)
oklchoklch(0.597 0.185 276.5)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.1997

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ebe266

#66b1eb · #9f66eb

#eb666e · #6eeb66

Split-complementary

Open in tool →

#eb9f66 · #b1eb66

#eb66b1 · #ebe266 · #66eb9f

Contrast

#666eeb as textRatioAAAA largeAAAFix
Aaon white
4.2:1failpassfail
  • AA: use #5d66ea as the text (4.61:1)
  • AAA: use #2f3be4 as the text (7.33:1)
  • AA: or shift the background to #0f0f0f (4.56:1)
Aaon black
4.99:1passpassfail
  • AAA: use #8a90f0 as the text (7.33:1)

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

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#666eeb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

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

tool url/palettes/new/666eeb-9e9cc4-df8f4e-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