Color

#b40424

#b40424
hex#b40424
rgbrgb(180, 4, 36)
hslhsl(349, 96%, 36%)
oklchoklch(0.487 0.195 23)
Closest name: Akai Red (#bc012e)Relative luminance 0.0992

Colors that go with #b40424

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 →

#04b494

#b4047c · #b43b04

#24b404 · #0424b4

Split-complementary

Open in tool →

#04b43b · #047cb4

#7cb404 · #04b494 · #3b04b4

Contrast

#b40424 as textRatioAAAA largeAAAFix
Aaon white
7.04:1passpasspassPasses AAA — no fix needed.
Aaon black
2.98:1failfailfail
  • AA: use #eb052f as the text (4.6:1)
  • AAA: use #fc5f7c as the text (7.07:1)
  • AA: or shift the background to #cfcfcf (4.52:1)
  • AAA: or shift the background to #ffffff (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b40424 as the background.

Brands using this color

Fonts for this mood

#b40424 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b40424
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 #b40424 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b40424-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