Color

#18b5cd

#18b5cd
hex#18b5cd
rgbrgb(24, 181, 205)
hslhsl(188, 79%, 45%)
oklchoklch(0.711 0.12 211.8)
Closest name: Aquarius (#2db0ce)Relative luminance 0.3765

Colors that go with #18b5cd

Charcoal, Denim 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 →

#cd3018

#18cd8b · #185bcd

#cd18b5 · #b5cd18

Split-complementary

Open in tool →

#cd185b · #cd8b18

#8b18cd · #cd3018 · #5bcd18

Contrast

#18b5cd as textRatioAAAA largeAAAFix
Aaon white
2.46:1failfailfail
  • AA: use #118192 as the text (4.59:1)
  • AAA: use #0d616e as the text (7.11:1)
  • AA: or shift the background to #3b3b3b (4.55:1)
  • AAA: or shift the background to #1a1a1a (7.07:1)
Aaon black
8.53:1passpasspassPasses 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 #18b5cd as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#18b5cd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #18b5cd
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 #18b5cd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/18b5cd-a2b7be-df4e81-1f252d-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