Color

#ff0505

#ff0505
hex#ff0505
rgbrgb(255, 5, 5)
hslhsl(0, 100%, 51%)
oklchoklch(0.629 0.257 29.1)
Closest name: red (#ff0000)Relative luminance 0.2138

Tints & shades

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

Harmonies

Complementary

Open in tool →

#05ffff

#ff0582 · #ff8205

#05ff05 · #0505ff

Split-complementary

Open in tool →

#05ff82 · #0582ff

#82ff05 · #05ffff · #8205ff

Contrast

#ff0505 as textRatioAAAA largeAAAFix
Aaon white
3.98:1failpassfail
  • AA: use #eb0000 as the text (4.63:1)
  • AAA: use #b30000 as the text (7.2:1)
  • AA: or shift the background to #171717 (4.5:1)
Aaon black
5.28:1passpassfail
  • AAA: use #ff6161 as the text (7.13:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #ff0505 as the background.

Brands using this color

Fonts for this mood

#ff0505 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #ff0505
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 #ff0505 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/ff0505-c4a19c-62cb98-2d251f-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