Color

#21d43f

#21d43f
hex#21d43f
rgbrgb(33, 212, 63)
hslhsl(130, 73%, 48%)
oklchoklch(0.759 0.232 144.6)
Closest name: Lime Green (#32cd32)Relative luminance 0.4777

Colors that go with #21d43f

Blue, Taupe and Violet 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 →

#d421b6

#5dd421 · #21d498

#3f21d4 · #d43f21

Split-complementary

Open in tool →

#9821d4 · #d4215d

#215dd4 · #d421b6 · #d49821

Contrast

#21d43f as textRatioAAAA largeAAAFix
Aaon white
1.99:1failfailfail
  • AA: use #158929 as the text (4.52:1)
  • AAA: use #10651e as the text (7.24:1)
  • AA: or shift the background to #474747 (4.67:1)
  • AAA: or shift the background to #2b2b2b (7.12:1)
Aaon black
10.55:1passpasspassPasses 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 #21d43f 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 #21d43f
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 #21d43f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21d43f-a2beaa-b14edf-1f2d28-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