#A89791

CSS

:root {
  --cortex: #a89791;
  --cortex-rgb: 168 151 145;
  --cortex-oklch: oklch(0.69 0.022 40.5);
}

.element {
  color: var(--cortex);
  background-color: hsl(16 12% 61%);
  border-color: oklch(0.69 0.022 40.5);
}

Tailwind CSS v4

@theme {
  --color-cortex: #a89791;
  --color-cortex-50: #fbf3f0;
  --color-cortex-100: #efe6e2;
  --color-cortex-200: #ddd1cd;
  --color-cortex-300: #c2b4af;
  --color-cortex-400: #ab9a95;
  --color-cortex-500: #94827b;
  --color-cortex-600: #7d6e68;
  --color-cortex-700: #645853;
  --color-cortex-800: #4a403d;
  --color-cortex-900: #332c2a;
  --color-cortex-950: #1f1917;
}

SCSS

$cortex: #a89791;
$cortex-rgb: 168, 151, 145;
$cortex-light: mix(#fff, $cortex, 20%);
$cortex-dark: mix(#000, $cortex, 20%);

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