#B50701

CSS

:root {
  --all-systems-red: #b50701;
  --all-systems-red-rgb: 181 7 1;
  --all-systems-red-oklch: oklch(0.488 0.197 29.6);
}

.element {
  color: var(--all-systems-red);
  background-color: hsl(2 99% 36%);
  border-color: oklch(0.488 0.197 29.6);
}

Tailwind CSS v4

@theme {
  --color-all-systems-red: #b50701;
  --color-all-systems-red-50: #ffe1d2;
  --color-all-systems-red-100: #ffd0bf;
  --color-all-systems-red-200: #ffb49f;
  --color-all-systems-red-300: #ff8d76;
  --color-all-systems-red-400: #fd6754;
  --color-all-systems-red-500: #ec392a;
  --color-all-systems-red-600: #c83326;
  --color-all-systems-red-700: #a1291e;
  --color-all-systems-red-800: #781b17;
  --color-all-systems-red-900: #55120f;
  --color-all-systems-red-950: #390303;
}

SCSS

$all-systems-red: #b50701;
$all-systems-red-rgb: 181, 7, 1;
$all-systems-red-light: mix(#fff, $all-systems-red, 20%);
$all-systems-red-dark: mix(#000, $all-systems-red, 20%);

.element {
  color: $all-systems-red;
  box-shadow: 0 0 0 2px rgba($all-systems-red, 0.35);
}