Color

#66a4e5

#66a4e5
hex#66a4e5
rgbrgb(102, 164, 229)
hslhsl(211, 71%, 65%)
oklchoklch(0.704 0.116 250.8)
Closest name: Acapulco Dive (#65a7dd)Relative luminance 0.3503

Colors that go with #66a4e5

Charcoal, Medium Sea 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 →

#e5a866

#66e3e5 · #6866e5

#e566a4 · #a4e566

Split-complementary

Open in tool →

#e56866 · #e3e566

#e566e3 · #e5a866 · #66e568

Contrast

#66a4e5 as textRatioAAAA largeAAAFix
Aaon white
2.62:1failfailfail
  • AA: use #2375cd as the text (4.67:1)
  • AAA: use #1b5a9d as the text (7.01:1)
  • AA: or shift the background to #363636 (4.61:1)
  • AAA: or shift the background to #141414 (7.02:1)
Aaon black
8.01:1passpasspassPasses 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 #66a4e5 as the background.

Brands using this color

Fonts for this mood

#66a4e5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #66a4e5
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 #66a4e5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/66a4e5-9cabc4-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