Color

#fb0921

#fb0921
hex#fb0921
rgbrgb(251, 9, 33)
hslhsl(354, 97%, 51%)
oklchoklch(0.623 0.251 26.7)
Closest name: red (#ff0000)Relative luminance 0.2081

Colors that go with #fb0921

Charcoal, Dodger Blue and Steel Blue 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 →

#09fbe3

#fb099a · #fb6a09

#21fb09 · #0921fb

Split-complementary

Open in tool →

#09fb6a · #099afb

#9afb09 · #09fbe3 · #6a09fb

Contrast

#fb0921 as textRatioAAAA largeAAAFix
Aaon white
4.07:1failpassfail
  • AA: use #ec041b as the text (4.57:1)
  • AAA: use #b50315 as the text (7.03:1)
  • AA: or shift the background to #141414 (4.53:1)
Aaon black
5.16:1passpassfail

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #fb0921 as the background.

Brands using this color

Fonts for this mood

#fb0921 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #fb0921
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 #fb0921 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/fb0921-c49d9c-62cb8e-2d241f-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