Color

#04b1fb

#04b1fb
hex#04b1fb
rgbrgb(4, 177, 251)
hslhsl(198, 97%, 50%)
oklchoklch(0.721 0.158 237.5)
Closest name: Cerulean (#55aaee)Relative luminance 0.3844

Colors that go with #04b1fb

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 →

#fb4e04

#04fbca · #0435fb

#fb04b1 · #b1fb04

Split-complementary

Open in tool →

#fb0435 · #fbca04

#ca04fb · #fb4e04 · #35fb04

Contrast

#04b1fb as textRatioAAAA largeAAAFix
Aaon white
2.42:1failfailfail
  • AA: use #037cb0 as the text (4.65:1)
  • AAA: use #025c83 as the text (7.34:1)
  • AA: or shift the background to #3b3b3b (4.63:1)
  • AAA: or shift the background to #1c1c1c (7.05:1)
Aaon black
8.69:1passpasspassPasses 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 #04b1fb as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#04b1fb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #04b1fb
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 #04b1fb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/04b1fb-9cb3c4-df4e69-1f232d-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