Color

#efff61

#efff61
hex#efff61
rgbrgb(239, 255, 97)
hslhsl(66, 100%, 69%)
oklchoklch(0.959 0.179 114.7)
Closest name: Biohazard Suit (#fbfb4c)Relative luminance 0.9073

Tints & shades

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

Harmonies

Complementary

Open in tool →

#7161ff

#ffc061 · #a0ff61

#61efff · #ff61ef

Split-complementary

Open in tool →

#61a0ff · #c061ff

#61ffc0 · #7161ff · #ff61a0

Contrast

#efff61 as textRatioAAAA largeAAAFix
Aaon white
1.1:1failfailfail
  • AA: use #6e7a00 as the text (4.72:1)
  • AAA: use #535c00 as the text (7.24:1)
  • AA: or shift the background to #707070 (4.52:1)
  • AAA: or shift the background to #525252 (7.12:1)
Aaon black
19.15:1passpasspassPasses 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 #efff61 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 #efff61
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 #efff61 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/efff61-b8bea2-4e86df-262d1f-f1eee9?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