#A66650

CSS

:root {
  --red-cent: #a66650;
  --red-cent-rgb: 166 102 80;
  --red-cent-oklch: oklch(0.575 0.089 39.7);
}

.element {
  color: var(--red-cent);
  background-color: hsl(15 35% 48%);
  border-color: oklch(0.575 0.089 39.7);
}

Tailwind CSS v4

@theme {
  --color-red-cent: #a66650;
  --color-red-cent-50: #ffede2;
  --color-red-cent-100: #ffdfd1;
  --color-red-cent-200: #f7c8b7;
  --color-red-cent-300: #e0a994;
  --color-red-cent-400: #cd8c76;
  --color-red-cent-500: #b97158;
  --color-red-cent-600: #9c604b;
  --color-red-cent-700: #7d4c3c;
  --color-red-cent-800: #5d372b;
  --color-red-cent-900: #41261d;
  --color-red-cent-950: #2a140d;
}

SCSS

$red-cent: #a66650;
$red-cent-rgb: 166, 102, 80;
$red-cent-light: mix(#fff, $red-cent, 20%);
$red-cent-dark: mix(#000, $red-cent, 20%);

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