#E31D45

CSS

:root {
  --crossing-the-line: #e31d45;
  --crossing-the-line-rgb: 227 29 69;
  --crossing-the-line-oklch: oklch(0.589 0.224 18.7);
}

.element {
  color: var(--crossing-the-line);
  background-color: hsl(348 78% 50%);
  border-color: oklch(0.589 0.224 18.7);
}

Tailwind CSS v4

@theme {
  --color-crossing-the-line: #e31d45;
  --color-crossing-the-line-50: #ffdcda;
  --color-crossing-the-line-100: #ffcac8;
  --color-crossing-the-line-200: #ffacab;
  --color-crossing-the-line-300: #ff8285;
  --color-crossing-the-line-400: #ff5669;
  --color-crossing-the-line-500: #f70947;
  --color-crossing-the-line-600: #d1143d;
  --color-crossing-the-line-700: #a81230;
  --color-crossing-the-line-800: #7d0925;
  --color-crossing-the-line-900: #590719;
  --color-crossing-the-line-950: #3c000a;
}

SCSS

$crossing-the-line: #e31d45;
$crossing-the-line-rgb: 227, 29, 69;
$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);
}