Color

#3fb9cf

#3fb9cf
hex#3fb9cf
rgbrgb(63, 185, 207)
hslhsl(189, 60%, 53%)
oklchoklch(0.728 0.109 212.1)
Closest name: Blue Bobbin (#52b4ca)Relative luminance 0.4026

Colors that go with #3fb9cf

Charcoal, Dark Orange and Denim 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 →

#cf553f

#3fcf9d · #3f72cf

#cf3fb9 · #b9cf3f

Split-complementary

Open in tool →

#cf3f72 · #cf9d3f

#9d3fcf · #cf553f · #72cf3f

Contrast

#3fb9cf as textRatioAAAA largeAAAFix
Aaon white
2.32:1failfailfail
  • AA: use #247f8f as the text (4.66:1)
  • AAA: use #1b5e6a as the text (7.35:1)
  • AA: or shift the background to #3d3d3d (4.68:1)
  • AAA: or shift the background to #1f1f1f (7.1:1)
Aaon black
9.05:1passpasspassPasses 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 #3fb9cf as the background.

Brands using this color

Fonts for this mood

#3fb9cf reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3fb9cf
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 #3fb9cf and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3fb9cf-a2b7be-df4e7e-1f252d-e9f1ee?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