Color

#21ed40

#21ed40
hex#21ed40
rgbrgb(33, 237, 64)
hslhsl(129, 85%, 53%)
oklchoklch(0.824 0.258 144.2)
Closest name: Becquerel (#4bec13)Relative luminance 0.6126

Colors that go with #21ed40

Violet, Deep Sky Blue and Taupe 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 →

#ed21ce

#69ed21 · #21eda6

#4021ed · #ed4021

Split-complementary

Open in tool →

#a621ed · #ed2169

#2169ed · #ed21ce · #eda621

Contrast

#21ed40 as textRatioAAAA largeAAAFix
Aaon white
1.58:1failfailfail
  • AA: use #0b891e as the text (4.55:1)
  • AAA: use #086316 as the text (7.48:1)
  • AA: or shift the background to #575757 (4.56:1)
  • AAA: or shift the background to #3b3b3b (7.07:1)
Aaon black
13.25:1passpasspassPasses 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 #21ed40 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 #21ed40
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 #21ed40 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21ed40-a2bea9-ae4edf-1f2d27-ecf1e9?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