Color

#b21601

#b21601
hex#b21601
rgbrgb(178, 22, 1)
hslhsl(7, 99%, 35%)
oklchoklch(0.487 0.189 30.9)
Closest name: All Systems Red (#b30103)Relative luminance 0.1004

Colors that go with #b21601

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 →

#019db2

#b20145 · #b26e01

#01b216 · #1601b2

Split-complementary

Open in tool →

#01b26e · #0145b2

#45b201 · #019db2 · #6e01b2

Contrast

#b21601 as textRatioAAAA largeAAAFix
Aaon white
6.98:1passpassfail
  • AAA: use #ad1501 as the text (7.28:1)
Aaon black
3.01:1failpassfail
  • AA: use #e91c01 as the text (4.63:1)
  • AAA: use #fe624d as the text (7.07:1)
  • AA: or shift the background to #d1d1d1 (4.57:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b21601 as the background.

Brands using this color

Fonts for this mood

#b21601 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b21601
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 #b21601 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b21601-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