Color

#51c313

#51c313
hex#51c313
rgbrgb(81, 195, 19)
hslhsl(99, 82%, 42%)
oklchoklch(0.722 0.219 138.3)
Closest name: Frog (#58bc08)Relative luminance 0.4083

Colors that go with #51c313

Blue, Charcoal and Royal 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 →

#8513c3

#a9c313 · #13c32e

#1351c3 · #c31351

Split-complementary

Open in tool →

#2e13c3 · #c313a9

#13a9c3 · #8513c3 · #c32e13

Contrast

#51c313 as textRatioAAAA largeAAAFix
Aaon white
2.29:1failfailfail
  • AA: use #38870d as the text (4.53:1)
  • AAA: use #28610a as the text (7.49:1)
  • AA: or shift the background to #404040 (4.53:1)
  • AAA: or shift the background to #212121 (7.03:1)
Aaon black
9.17:1passpasspassPasses 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 #51c313 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 #51c313
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 #51c313 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/51c313-a8bea2-664edf-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