Color

#b4040a

#b4040a
hex#b4040a
rgbrgb(180, 4, 10)
hslhsl(358, 96%, 36%)
oklchoklch(0.485 0.197 28.3)
Closest name: All Systems Red (#b30103)Relative luminance 0.0981

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#04b4ae

#b40462 · #b45604

#0ab404 · #040ab4

Split-complementary

Open in tool →

#04b456 · #0462b4

#62b404 · #04b4ae · #5604b4

Contrast

#b4040a as textRatioAAAA largeAAAFix
Aaon white
7.09:1passpasspassPasses AAA — no fix needed.
Aaon black
2.96:1failfailfail
  • AA: use #eb050c as the text (4.56:1)
  • AAA: use #fc6469 as the text (7.17:1)
  • AA: or shift the background to #cfcfcf (4.55:1)
  • AAA: or shift the background to #ffffff (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b4040a as the background.

Brands using this color

Fonts for this mood

#b4040a reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b4040a
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #b4040a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b4040a-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