Color

#21fd49

#21fd49
hex#21fd49
rgbrgb(33, 253, 73)
hslhsl(131, 98%, 56%)
oklchoklch(0.866 0.269 144.6)
Closest name: Cathode Green (#00ff55)Relative luminance 0.7105

Colors that go with #21fd49

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 →

#fd21d4

#66fd21 · #21fdb7

#4921fd · #fd4921

Split-complementary

Open in tool →

#b721fd · #fd2166

#2166fd · #fd21d4 · #fdb721

Contrast

#21fd49 as textRatioAAAA largeAAAFix
Aaon white
1.38:1failfailfail
  • AA: use #01881a as the text (4.63:1)
  • AAA: use #016513 as the text (7.31:1)
  • AA: or shift the background to #5e5e5e (4.7:1)
  • AAA: or shift the background to #424242 (7.28:1)
Aaon black
15.21:1passpasspassPasses 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 #21fd49 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 #21fd49
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 #21fd49 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21fd49-a2beaa-b34edf-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