Color

#b5171d

#b5171d
hex#b5171d
rgbrgb(181, 23, 29)
hslhsl(358, 77%, 40%)
oklchoklch(0.495 0.189 26.5)
Closest name: firebrick (#b22222)Relative luminance 0.1053

Colors that go with #b5171d

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 →

#17b5af

#b5176b · #b56117

#1db517 · #171db5

Split-complementary

Open in tool →

#17b561 · #176bb5

#6bb517 · #17b5af · #6117b5

Contrast

#b5171d as textRatioAAAA largeAAAFix
Aaon white
6.76:1passpassfail
  • AAA: use #b0171c as the text (7.03:1)
Aaon black
3.11:1failpassfail
  • AA: use #e3262d as the text (4.58:1)
  • AAA: use #ec6f73 as the text (7.09:1)
  • AA: or shift the background to #d4d4d4 (4.56:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b5171d as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#b5171d reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b5171d
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 #b5171d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b5171d-c49f9c-62cb95-2d251f-f1e9ed?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