Color

#666ee1

#666ee1
hex#666ee1
rgbrgb(102, 110, 225)
hslhsl(236, 67%, 64%)
oklchoklch(0.59 0.172 276.8)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.1941

Tints & shades

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

Harmonies

Complementary

Open in tool →

#e1d966

#66abe1 · #9b66e1

#e1666e · #6ee166

Split-complementary

Open in tool →

#e19b66 · #abe166

#e166ab · #e1d966 · #66e19b

Contrast

#666ee1 as textRatioAAAA largeAAAFix
Aaon white
4.3:1failpassfail
  • AA: use #616ae0 as the text (4.52:1)
  • AAA: use #3742d7 as the text (7.18:1)
  • AA: or shift the background to #0d0d0d (4.52:1)
Aaon black
4.88:1passpassfail
  • AAA: use #888ee7 as the text (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666ee1 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

#666ee1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #666ee1
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 #666ee1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666ee1-9e9cc4-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