Color

#4efd51

#4efd51
hex#4efd51
rgbrgb(78, 253, 81)
hslhsl(121, 98%, 65%)
oklchoklch(0.873 0.255 143.2)
Closest name: Cathode Green (#00ff55)Relative luminance 0.7246

Colors that go with #4efd51

Violet, Hot Pink and Plum 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 →

#fd4efa

#a3fd4e · #4efda9

#514efd · #fd514e

Split-complementary

Open in tool →

#a94efd · #fd4ea3

#4ea3fd · #fd4efa · #fda94e

Contrast

#4efd51 as textRatioAAAA largeAAAFix
Aaon white
1.36:1failfailfail
  • AA: use #018804 as the text (4.64:1)
  • AAA: use #016503 as the text (7.33:1)
  • AA: or shift the background to #616161 (4.57:1)
  • AAA: or shift the background to #454545 (7.07:1)
Aaon black
15.49:1passpasspassPasses 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 #4efd51 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 #4efd51
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 #4efd51 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/4efd51-a2bea6-9b4edf-1f2d26-edf1e9?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