Color

#51b366

#51b366
hex#51b366
rgbrgb(81, 179, 102)
hslhsl(133, 39%, 51%)
oklchoklch(0.689 0.145 148.4)
Closest name: mediumseagreen (#3cb371)Relative luminance 0.3495

Tints & shades

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

Harmonies

Complementary

Open in tool →

#b3519e

#6db351 · #51b397

#6651b3 · #b36651

Split-complementary

Open in tool →

#9751b3 · #b3516d

#516db3 · #b3519e · #b39751

Contrast

#51b366 as textRatioAAAA largeAAAFix
Aaon white
2.63:1failfailfail
  • AA: use #3a8349 as the text (4.64:1)
  • AAA: use #2c6338 as the text (7.12:1)
  • AA: or shift the background to #363636 (4.6:1)
  • AAA: or shift the background to #141414 (7.01:1)
Aaon black
7.99:1passpasspassPasses 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 #51b366 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 #51b366
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #51b366 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/51b366-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