Color

#3eb1ef

#3eb1ef
hex#3eb1ef
rgbrgb(62, 177, 239)
hslhsl(201, 85%, 59%)
oklchoklch(0.723 0.135 236.9)
Closest name: Cerulean (#55aaee)Relative luminance 0.387

Colors that go with #3eb1ef

Charcoal, Dark Orange and Amber 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 →

#ef7c3e

#3eefd5 · #3e58ef

#ef3eb1 · #b1ef3e

Split-complementary

Open in tool →

#ef3e58 · #efd53e

#d53eef · #ef7c3e · #58ef3e

Contrast

#3eb1ef as textRatioAAAA largeAAAFix
Aaon white
2.4:1failfailfail
  • AA: use #0f7db8 as the text (4.52:1)
  • AAA: use #0b5d89 as the text (7.14:1)
  • AA: or shift the background to #3d3d3d (4.52:1)
  • AAA: or shift the background to #1c1c1c (7.09:1)
Aaon black
8.74:1passpasspassPasses 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 #3eb1ef as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#3eb1ef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3eb1ef
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 #3eb1ef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3eb1ef-9cb1c4-df4e62-1f222d-e9f1f0?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