Color

#40d3ed

#40d3ed
hex#40d3ed
rgbrgb(64, 211, 237)
hslhsl(189, 83%, 59%)
oklchoklch(0.802 0.125 212.2)
Closest name: darkturquoise (#00ced1)Relative luminance 0.5379

Colors that go with #40d3ed

Charcoal, Crimson and Dodger Blue 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 →

#ed5a40

#40edb0 · #407ced

#ed40d3 · #d3ed40

Split-complementary

Open in tool →

#ed407c · #edb040

#b040ed · #ed5a40 · #7ced40

Contrast

#40d3ed as textRatioAAAA largeAAAFix
Aaon white
1.79:1failfailfail
  • AA: use #0e8195 as the text (4.57:1)
  • AAA: use #0a6170 as the text (7.1:1)
  • AA: or shift the background to #4f4f4f (4.59:1)
  • AAA: or shift the background to #333333 (7.07:1)
Aaon black
11.76:1passpasspassPasses 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 #40d3ed as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#40d3ed reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #40d3ed
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 #40d3ed and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/40d3ed-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