Color

#40a4fc

#40a4fc
hex#40a4fc
rgbrgb(64, 164, 252)
hslhsl(208, 97%, 62%)
oklchoklch(0.701 0.159 248.8)
Closest name: Cerulean (#55aaee)Relative luminance 0.3467

Colors that go with #40a4fc

Charcoal, Tomato 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 →

#fc9840

#40fcf6 · #4046fc

#fc40a4 · #a4fc40

Split-complementary

Open in tool →

#fc4046 · #fcf640

#f640fc · #fc9840 · #46fc40

Contrast

#40a4fc as textRatioAAAA largeAAAFix
Aaon white
2.65:1failfailfail
  • AA: use #0375d8 as the text (4.63:1)
  • AAA: use #0257a1 as the text (7.29:1)
  • AA: or shift the background to #363636 (4.57:1)
  • AAA: or shift the background to #121212 (7.08:1)
Aaon black
7.93:1passpasspassPasses 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 #40a4fc as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#40a4fc reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #40a4fc
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 #40a4fc and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/40a4fc-9cadc4-df4e51-1f212d-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