CSS color

red

#ff0000

hex#ff0000

rgbrgb(255, 0, 0)

hslhsl(0, 100%, 50%)

oklchoklch(0.628 0.258 29.2)

Relative luminance 0.2126

Warm Vivid Playful Bold

Open in palette tool Check contrast

Red on this page is the real value, not a screenshot: exact hex, RGB, HSL and OKLCH, ten tints and ten shades, classic harmonies, and WCAG contrast with fixes — plus the 1 public brand that uses it and the palettes it appears in.

Tints & shades

Tints — toward white

ff1a1a ff3333 ff4747 ff6161 ff7a7a ff9494 ffadad ffc2c2 ffdbdb fff5f5

Shades — toward black

e60000 d10000 b80000 a30000 8a0000 700000 5c0000 420000 2e0000 140000

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

Harmonies

Complementary

Open in tool →

ff0000 00ffff

#00ffff

Analogous

Open in tool →

ff0000 ff0080 ff8000

#ff0080 · #ff8000

Triadic

Open in tool →

ff0000 00ff00 0000ff

#00ff00 · #0000ff

Split-complementary

Open in tool →

ff0000 00ff80 0080ff

#00ff80 · #0080ff

Tetradic

Open in tool →

ff0000 80ff00 00ffff 8000ff

#80ff00 · #00ffff · #8000ff

Contrast

red as text	Ratio	AA	AA large	AAA	Fix
Aaon white	4:1	fail	pass	fail	AA: use #eb0000 as the text (4.63:1) AAA: use #b30000 as the text (7.2:1) AA: or shift the background to #141414 (4.61:1)
Aaon black	5.25:1	pass	pass	fail	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 red as the background.

Brands using this color

Paddlesecondary · #ff0000

Fonts for this mood

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

Warm fonts →Playful fonts →Bold fonts →

mcpConnect your agent — build around red

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 #ff0000 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/ff0000-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