Color

#66cd51

#66cd51
hex#66cd51
rgbrgb(102, 205, 81)
hslhsl(110, 55%, 56%)
oklchoklch(0.76 0.189 140.4)
Closest name: Blinking Terminal (#66cc00)Relative luminance 0.4708

Colors that go with #66cd51

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 →

#b851cd

#a3cd51 · #51cd7a

#5166cd · #cd5166

Split-complementary

Open in tool →

#7a51cd · #cd51a3

#51a3cd · #b851cd · #cd7a51

Contrast

#66cd51 as textRatioAAAA largeAAAFix
Aaon white
2.02:1failfailfail
  • AA: use #378627 as the text (4.56:1)
  • AAA: use #28631d as the text (7.26:1)
  • AA: or shift the background to #474747 (4.61:1)
  • AAA: or shift the background to #2b2b2b (7.02:1)
Aaon black
10.42:1passpasspassPasses 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 #66cd51 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 #66cd51
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 #66cd51 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/66cd51-a3bea2-814edf-1f2d23-eef1e9?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