CSS named color
Crimson #DC143C
Crimson is vivid red. Below: every color format, WCAG contrast against black and white, its tints, shades and tones, and the harmonies that pair with it.
Color values
Contrast & accessibility
WCAG contrast ratio of Crimson used as a foreground on white and black backgrounds.
On white
On black
Tints, shades & tones
Systematic variations of Crimson — click any swatch to copy its hex.
Simulated colour vision
How Crimson reads under the four common colour-vision deficiencies, using the standard Machado (2009) matrices at full severity. A simulation, not a measurement of any one person's vision; the point is whether this colour still does its job when hue drops out.
#DC143CTailwind-style ramp
Eleven steps from 50 to 950 with the hue and saturation of Crimson held and only lightness stepped. Computed, not curated: the 500 step sits closest to the source, which is where Tailwind puts a brand colour.
Color harmonies
Palettes built from Crimson by rotating its hue. Each swatch links to its closest named color.
Complementary
Split-complementary
Use Crimson in your stack
Tailwind (arbitrary value)
Works for any property: text-[#dc143c], border-[#dc143c].
CSS custom property
Reference it anywhere with var(--color).
Build a full theme
Turn Crimson into a complete shadcn/ui palette — light & dark, contrast-checked, one-command install.
Extract a theme →