Color

#66a6ea

#66a6ea
hex#66a6ea
rgbrgb(102, 166, 234)
hslhsl(211, 76%, 66%)
oklchoklch(0.71 0.12 251.2)
Closest name: Cerulean (#55aaee)Relative luminance 0.3604

Colors that go with #66a6ea

Charcoal, Emerald Green and Peru 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 →

#eaaa66

#66e8ea · #6966ea

#ea66a6 · #a6ea66

Split-complementary

Open in tool →

#ea6966 · #e8ea66

#ea66e8 · #eaaa66 · #66ea69

Contrast

#66a6ea as textRatioAAAA largeAAAFix
Aaon white
2.56:1failfailfail
  • AA: use #1d75d3 as the text (4.63:1)
  • AAA: use #1659a2 as the text (7.04:1)
  • AA: or shift the background to #383838 (4.58:1)
  • AAA: or shift the background to #171717 (7.01:1)
Aaon black
8.21:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #66a6ea as the background.

Brands using this color

Fonts for this mood

#66a6ea reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #66a6ea
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 #66a6ea and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/66a6ea-9cabc4-df534e-1f202d-e9f1f1?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