Color

#40c3dd

#40c3dd
hex#40c3dd
rgbrgb(64, 195, 221)
hslhsl(190, 70%, 56%)
oklchoklch(0.758 0.116 213.9)
Closest name: Blue Martini (#52b4d3)Relative luminance 0.4534

Colors that go with #40c3dd

Charcoal, Dark Salmon and Crimson 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 →

#dd5a40

#40dda9 · #4075dd

#dd40c3 · #c3dd40

Split-complementary

Open in tool →

#dd4075 · #dda940

#a940dd · #dd5a40 · #75dd40

Contrast

#40c3dd as textRatioAAAA largeAAAFix
Aaon white
2.09:1failfailfail
  • AA: use #1a7f93 as the text (4.67:1)
  • AAA: use #146171 as the text (7.05:1)
  • AA: or shift the background to #454545 (4.6:1)
  • AAA: or shift the background to #262626 (7.26:1)
Aaon black
10.07:1passpasspassPasses 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 #40c3dd as the background.

Brands using this color

Fonts for this mood

#40c3dd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #40c3dd
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 #40c3dd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/40c3dd-a2b6be-df4e7c-1f252d-e9f1ef?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