#8B4736

CSS

:root {
  --olive-nicoise: #8b4736;
  --olive-nicoise-rgb: 139 71 54;
  --olive-nicoise-oklch: oklch(0.478 0.097 35.1);
}

.element {
  color: var(--olive-nicoise);
  background-color: hsl(12 44% 38%);
  border-color: oklch(0.478 0.097 35.1);
}

Tailwind CSS v4

@theme {
  --color-olive-nicoise: #8b4736;
  --color-olive-nicoise-50: #ffece2;
  --color-olive-nicoise-100: #ffddd1;
  --color-olive-nicoise-200: #fac7b7;
  --color-olive-nicoise-300: #e4a794;
  --color-olive-nicoise-400: #d18a77;
  --color-olive-nicoise-500: #bd6d59;
  --color-olive-nicoise-600: #a05d4c;
  --color-olive-nicoise-700: #804a3c;
  --color-olive-nicoise-800: #5f352c;
  --color-olive-nicoise-900: #43241e;
  --color-olive-nicoise-950: #2b130e;
}

SCSS

$olive-nicoise: #8b4736;
$olive-nicoise-rgb: 139, 71, 54;
$olive-nicoise-light: mix(#fff, $olive-nicoise, 20%);
$olive-nicoise-dark: mix(#000, $olive-nicoise, 20%);

.element {
  color: $olive-nicoise;
  box-shadow: 0 0 0 2px rgba($olive-nicoise, 0.35);
}