Color

#666fea

#666fea
hex#666fea
rgbrgb(102, 111, 234)
hslhsl(236, 76%, 66%)
oklchoklch(0.598 0.183 276.2)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2013

Tints & shades

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

Harmonies

Complementary

Open in tool →

#eae166

#66b1ea · #a066ea

#ea666f · #6fea66

Split-complementary

Open in tool →

#eaa066 · #b1ea66

#ea66b1 · #eae166 · #66eaa0

Contrast

#666fea as textRatioAAAA largeAAAFix
Aaon white
4.18:1failpassfail
  • AA: use #5d67e9 as the text (4.58:1)
  • AAA: use #313ce3 as the text (7.28:1)
  • AA: or shift the background to #0f0f0f (4.59:1)
Aaon black
5.03:1passpassfail
  • AAA: use #868dee as the text (7.06:1)

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

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

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

tool url/palettes/new/666fea-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