Color

#effb04

#effb04
hex#effb04
rgbrgb(239, 251, 4)
hslhsl(63, 97%, 50%)
oklchoklch(0.947 0.211 113.3)
Closest name: Banana Flash (#eefe02)Relative luminance 0.8735

Tints & shades

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

Harmonies

Complementary

Open in tool →

#1004fb

#fb8c04 · #73fb04

#04effb · #fb04ef

Split-complementary

Open in tool →

#0473fb · #8c04fb

#04fb8c · #1004fb · #fb0473

Contrast

#effb04 as textRatioAAAA largeAAAFix
Aaon white
1.14:1failfailfail
  • AA: use #737902 as the text (4.7:1)
  • AAA: use #565a01 as the text (7.35:1)
  • AA: or shift the background to #6b6b6b (4.69:1)
  • AAA: or shift the background to #4f4f4f (7.2:1)
Aaon black
18.47:1passpasspassPasses 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 #effb04 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 #effb04
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 #effb04 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/effb04-b9bea2-4e8ddf-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