Color

#81ff42

#81ff42
hex#81ff42
rgbrgb(129, 255, 66)
hslhsl(100, 100%, 63%)
oklchoklch(0.893 0.246 137.5)
Closest name: Acid Green (#8ffe09)Relative luminance 0.7658

Colors that go with #81ff42

Violet, Charcoal 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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#c042ff

#e0ff42 · #42ff62

#4281ff · #ff4281

Split-complementary

Open in tool →

#6242ff · #ff42e0

#42e0ff · #c042ff · #ff6242

Contrast

#81ff42 as textRatioAAAA largeAAAFix
Aaon white
1.29:1failfailfail
  • AA: use #2c8500 as the text (4.71:1)
  • AAA: use #226600 as the text (7.07:1)
  • AA: or shift the background to #636363 (4.67:1)
  • AAA: or shift the background to #474747 (7.22:1)
Aaon black
16.32:1passpasspassPasses 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 #81ff42 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 #81ff42
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 #81ff42 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/81ff42-a8bea2-694edf-1f2d21-f0f1e9?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