Color

#21b52e

#21b52e
hex#21b52e
rgbrgb(33, 181, 46)
hslhsl(125, 69%, 42%)
oklchoklch(0.675 0.209 143.7)
Closest name: Green Glimmer (#00bb00)Relative luminance 0.3357

Colors that go with #21b52e

Royal Blue, Taupe and Fuchsia 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 →

#b521a9

#5fb521 · #21b577

#2e21b5 · #b52e21

Split-complementary

Open in tool →

#7721b5 · #b5215f

#215fb5 · #b521a9 · #b57721

Contrast

#21b52e as textRatioAAAA largeAAAFix
Aaon white
2.72:1failfailfail
  • AA: use #198622 as the text (4.69:1)
  • AAA: use #13671a as the text (7.04:1)
  • AA: or shift the background to #333333 (4.64:1)
  • AAA: or shift the background to #0f0f0f (7.04:1)
Aaon black
7.71:1passpasspassPasses 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 #21b52e 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 #21b52e
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 #21b52e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21b52e-a2bea7-a54edf-1f2d26-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