#E21F41

CSS

:root {
  --crossing-the-line: #e21f41;
  --crossing-the-line-rgb: 226 31 65;
  --crossing-the-line-oklch: oklch(0.587 0.222 20);
}

.element {
  color: var(--crossing-the-line);
  background-color: hsl(350 77% 50%);
  border-color: oklch(0.587 0.222 20);
}

Tailwind CSS v4

@theme {
  --color-crossing-the-line: #e21f41;
  --color-crossing-the-line-50: #ffddd9;
  --color-crossing-the-line-100: #ffcac6;
  --color-crossing-the-line-200: #ffaca9;
  --color-crossing-the-line-300: #ff8383;
  --color-crossing-the-line-400: #ff5765;
  --color-crossing-the-line-500: #f71043;
  --color-crossing-the-line-600: #d0173a;
  --color-crossing-the-line-700: #a8142e;
  --color-crossing-the-line-800: #7d0b23;
  --color-crossing-the-line-900: #590817;
  --color-crossing-the-line-950: #3b0009;
}

SCSS

$crossing-the-line: #e21f41;
$crossing-the-line-rgb: 226, 31, 65;
$crossing-the-line-light: mix(#fff, $crossing-the-line, 20%);
$crossing-the-line-dark: mix(#000, $crossing-the-line, 20%);

.element {
  color: $crossing-the-line;
  box-shadow: 0 0 0 2px rgba($crossing-the-line, 0.35);
}