Color

#b00306

#b00306
hex#b00306
rgbrgb(176, 3, 6)
hslhsl(359, 97%, 35%)
oklchoklch(0.477 0.194 28.7)
Closest name: All Systems Red (#b30103)Relative luminance 0.0931

Tints & shades

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

Harmonies

Complementary

Open in tool →

#03b0ad

#b0035c · #b05603

#06b003 · #0306b0

Split-complementary

Open in tool →

#03b056 · #035cb0

#5cb003 · #03b0ad · #5603b0

Contrast

#b00306 as textRatioAAAA largeAAAFix
Aaon white
7.34:1passpasspassPasses AAA — no fix needed.
Aaon black
2.86:1failfailfail
  • AA: use #ec0407 as the text (4.59:1)
  • AAA: use #fd6366 as the text (7.15:1)
  • AA: or shift the background to #cccccc (4.57:1)
  • AAA: or shift the background to #fafafa (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #b00306 as the background.

Brands using this color

Fonts for this mood

#b00306 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #b00306
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 #b00306 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/b00306-c4a09c-62cb96-2d251f-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