Color

#21fd50

#21fd50
hex#21fd50
rgbrgb(33, 253, 80)
hslhsl(133, 98%, 56%)
oklchoklch(0.866 0.265 145.1)
Closest name: Cathode Green (#00ff55)Relative luminance 0.7115

Colors that go with #21fd50

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 →

#fd21cd

#5ffd21 · #21fdbe

#5021fd · #fd5021

Split-complementary

Open in tool →

#be21fd · #fd215f

#215ffd · #fd21cd · #fdbe21

Contrast

#21fd50 as textRatioAAAA largeAAAFix
Aaon white
1.38:1failfailfail
  • AA: use #01881f as the text (4.62:1)
  • AAA: use #016517 as the text (7.3:1)
  • AA: or shift the background to #5e5e5e (4.7:1)
  • AAA: or shift the background to #424242 (7.29:1)
Aaon black
15.23:1passpasspassPasses 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 #21fd50 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 #21fd50
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 #21fd50 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21fd50-a2beab-b84edf-1f2d28-ebf1e9?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