Color

#3fb3e9

#3fb3e9
hex#3fb3e9
rgbrgb(63, 179, 233)
hslhsl(199, 79%, 58%)
oklchoklch(0.725 0.128 232.9)
Closest name: Blue Bikini (#00bbee)Relative luminance 0.3918

Colors that go with #3fb3e9

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 →

#e9753f

#3fe9c9 · #3f5ee9

#e93fb3 · #b3e93f

Split-complementary

Open in tool →

#e93f5e · #e9c93f

#c93fe9 · #e9753f · #5ee93f

Contrast

#3fb3e9 as textRatioAAAA largeAAAFix
Aaon white
2.38:1failfailfail
  • AA: use #147dad as the text (4.6:1)
  • AAA: use #105f84 as the text (7.02:1)
  • AA: or shift the background to #3d3d3d (4.57:1)
  • AAA: or shift the background to #1c1c1c (7.17:1)
Aaon black
8.84:1passpasspassPasses 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 #3fb3e9 as the background.

Brands using this color

Fonts for this mood

#3fb3e9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3fb3e9
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 #3fb3e9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3fb3e9-9cb3c4-df4e66-1f232d-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