Color

#ef3101

#ef3101
hex#ef3101
rgbrgb(239, 49, 1)
hslhsl(12, 99%, 47%)
oklchoklch(0.617 0.228 32.8)
Closest name: Arcade Fire (#ee3311)Relative luminance 0.2055

Tints & shades

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

Harmonies

Complementary

Open in tool →

#01bfef

#ef0148 · #efa701

#01ef31 · #3101ef

Split-complementary

Open in tool →

#01efa7 · #0148ef

#48ef01 · #01bfef · #a701ef

Contrast

#ef3101 as textRatioAAAA largeAAAFix
Aaon white
4.11:1failpassfail
  • AA: use #df2e01 as the text (4.64:1)
  • AAA: use #a72201 as the text (7.31:1)
  • AA: or shift the background to #121212 (4.56:1)
Aaon black
5.11:1passpassfail
  • AAA: use #fe653e as the text (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #ef3101 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#ef3101 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #ef3101
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 #ef3101 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/ef3101-c4a99c-62cbad-2d281f-f1e9ec?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