Color

#21e4e0

#21e4e0
hex#21e4e0
rgbrgb(33, 228, 224)
hslhsl(179, 78%, 51%)
oklchoklch(0.833 0.139 192.5)
Closest name: turquoise (#40e0d0)Relative luminance 0.6119

Colors that go with #21e4e0

Charcoal, Crimson and Deep Sky 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.

Real palettes that use #21e4e0

Tints & shades

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

Harmonies

Complementary

Open in tool →

#e42124

#21e47f · #2185e4

#e021e4 · #e4e021

Split-complementary

Open in tool →

#e42185 · #e47f21

#7f21e4 · #e42124 · #85e421

Contrast

#21e4e0 as textRatioAAAA largeAAAFix
Aaon white
1.59:1failfailfail
  • AA: use #108482 as the text (4.52:1)
  • AAA: use #0c5f5e as the text (7.46:1)
  • AA: or shift the background to #575757 (4.56:1)
  • AAA: or shift the background to #3b3b3b (7.06:1)
Aaon black
13.24:1passpasspassPasses 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 #21e4e0 as the background.

Brands using this color

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

mcpConnect your agent — build around #21e4e0
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 #21e4e0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21e4e0-a2bbbe-d45996-1f272d-e9f1ed?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