Color

#ef1d01

#ef1d01
hex#ef1d01
rgbrgb(239, 29, 1)
hslhsl(7, 99%, 47%)
oklchoklch(0.606 0.238 30.6)
Closest name: Assassin’s Red (#f60206)Relative luminance 0.1923

Colors that go with #ef1d01

Charcoal, Royal Blue and Sea Green 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 →

#01d3ef

#ef015c · #ef9401

#01ef1d · #1d01ef

Split-complementary

Open in tool →

#01ef94 · #015cef

#5cef01 · #01d3ef · #9401ef

Contrast

#ef1d01 as textRatioAAAA largeAAAFix
Aaon white
4.33:1failpassfail
  • AA: use #e91c01 as the text (4.53:1)
  • AAA: use #ad1501 as the text (7.28:1)
  • AA: or shift the background to #0a0a0a (4.57:1)
Aaon black
4.85:1passpassfail
  • AAA: use #fe624d as the text (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #ef1d01 as the background.

Brands using this color

Fonts for this mood

#ef1d01 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #ef1d01
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 #ef1d01 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/ef1d01-c4a59c-62cba4-2d271f-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