Color

#21a8ca

#21a8ca
hex#21a8ca
rgbrgb(33, 168, 202)
hslhsl(192, 72%, 46%)
oklchoklch(0.679 0.117 220.3)
Closest name: Aquarius (#2db0ce)Relative luminance 0.3259

Colors that go with #21a8ca

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.

Real palettes that use #21a8ca

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#ca4321

#21ca97 · #2154ca

#ca21a8 · #a8ca21

Split-complementary

Open in tool →

#ca2154 · #ca9721

#9721ca · #ca4321 · #54ca21

Contrast

#21a8ca as textRatioAAAA largeAAAFix
Aaon white
2.79:1failfailfail
  • AA: use #19809a as the text (4.57:1)
  • AAA: use #135f72 as the text (7.22:1)
  • AA: or shift the background to #333333 (4.52:1)
  • AAA: or shift the background to #0a0a0a (7.09:1)
Aaon black
7.52:1passpasspassPasses 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 #21a8ca as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#21a8ca reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #21a8ca
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 #21a8ca and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21a8ca-a2b5be-df4e77-1f242d-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