Color

#b21532

#b21532
hex#b21532
rgbrgb(178, 21, 50)
hslhsl(349, 79%, 39%)
oklchoklch(0.491 0.186 19.6)
Closest name: Active Volcano (#bb1133)Relative luminance 0.1023

Colors that go with #b21532

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 →

#15b295

#b21580 · #b24715

#32b215 · #1532b2

Split-complementary

Open in tool →

#15b247 · #1580b2

#80b215 · #15b295 · #4715b2

Contrast

#b21532 as textRatioAAAA largeAAAFix
Aaon white
6.89:1passpassfail
  • AAA: use #ad1430 as the text (7.19:1)
Aaon black
3.05:1failpassfail
  • AA: use #e41b40 as the text (4.53:1)
  • AAA: use #ee6d85 as the text (7.16:1)
  • 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 #b21532 as the background.

Brands using this color

Fonts for this mood

#b21532 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b21532
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 #b21532 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b21532-c49c9f-62cb85-2d231f-f1e9ee?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