Color

#b2180a

#b2180a
hex#b2180a
rgbrgb(178, 24, 10)
hslhsl(5, 89%, 37%)
oklchoklch(0.489 0.188 30.1)
Closest name: All Systems Red (#b30103)Relative luminance 0.1014

Colors that go with #b2180a

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 →

#0aa4b2

#b20a50 · #b26c0a

#0ab218 · #180ab2

Split-complementary

Open in tool →

#0ab26c · #0a50b2

#50b20a · #0aa4b2 · #6c0ab2

Contrast

#b2180a as textRatioAAAA largeAAAFix
Aaon white
6.94:1passpassfail
  • AAA: use #ae180a as the text (7.16:1)
Aaon black
3.03:1failpassfail
  • AA: use #e7200d as the text (4.61:1)
  • AAA: use #f5685b as the text (7.01:1)
  • AA: or shift the background to #d1d1d1 (4.54:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b2180a as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#b2180a reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b2180a
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 #b2180a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b2180a-c4a49c-62cba1-2d261f-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