Color

#66bf5a

#66bf5a
hex#66bf5a
rgbrgb(102, 191, 90)
hslhsl(113, 44%, 55%)
oklchoklch(0.726 0.163 141.4)
Closest name: Bermudagrass (#6bc271)Relative luminance 0.4082

Colors that go with #66bf5a

Charcoal, Dark Olive Green 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 →

#b35abf

#98bf5a · #5abf80

#5a66bf · #bf5a66

Split-complementary

Open in tool →

#805abf · #bf5a98

#5a98bf · #b35abf · #bf805a

Contrast

#66bf5a as textRatioAAAA largeAAAFix
Aaon white
2.29:1failfailfail
  • AA: use #3d8433 as the text (4.62:1)
  • AAA: use #2e6327 as the text (7.17:1)
  • AA: or shift the background to #404040 (4.53:1)
  • AAA: or shift the background to #212121 (7.03:1)
Aaon black
9.16:1passpasspassPasses 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 #66bf5a as the background.

Brands using this color

Palettes built around it

mcpConnect your agent — build around #66bf5a
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 #66bf5a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/66bf5a-a2bea2-884edf-1f2d24-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