Color

#b41504

#b41504
hex#b41504
rgbrgb(180, 21, 4)
hslhsl(6, 96%, 36%)
oklchoklch(0.491 0.191 30.4)
Closest name: All Systems Red (#b30103)Relative luminance 0.1025

Colors that go with #b41504

Royal Blue, Steel Blue and Teal 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 →

#04a2b4

#b4044a · #b46d04

#04b415 · #1504b4

Split-complementary

Open in tool →

#04b46d · #044ab4

#4ab404 · #04a2b4 · #6d04b4

Contrast

#b41504 as textRatioAAAA largeAAAFix
Aaon white
6.89:1passpassfail
  • AAA: use #af1504 as the text (7.16:1)
Aaon black
3.05:1failpassfail
  • AA: use #e61b05 as the text (4.52:1)
  • AAA: use #fc6655 as the text (7.17:1)
  • AA: or shift the background to #d1d1d1 (4.51:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b41504 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#b41504 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b41504
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 #b41504 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b41504-c4a59c-62cba3-2d271f-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