Color

#b30915

#b30915
hex#b30915
rgbrgb(179, 9, 21)
hslhsl(356, 90%, 37%)
oklchoklch(0.485 0.194 26.9)
Closest name: All Systems Red (#b30103)Relative luminance 0.0983

Tints & shades

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

Harmonies

Complementary

Open in tool →

#09b3a8

#b3096a · #b35309

#15b309 · #0915b3

Split-complementary

Open in tool →

#09b353 · #096ab3

#6ab309 · #09b3a8 · #5309b3

Contrast

#b30915 as textRatioAAAA largeAAAFix
Aaon white
7.08:1passpasspassPasses AAA — no fix needed.
Aaon black
2.97:1failfailfail
  • AA: use #e90c1b as the text (4.53:1)
  • AAA: use #f7646e as the text (7:1)
  • AA: or shift the background to #cfcfcf (4.54:1)
  • AAA: or shift the background to #ffffff (7.08:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b30915 as the background.

Brands using this color

Fonts for this mood

#b30915 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b30915
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 #b30915 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b30915-c49e9c-62cb91-2d241f-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