#81716B

CSS

:root {
  --acoustic-brown: #81716b;
  --acoustic-brown-rgb: 129 113 107;
  --acoustic-brown-oklch: oklch(0.562 0.022 41.7);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(16 9% 46%);
  border-color: oklch(0.562 0.022 41.7);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #81716b;
  --color-acoustic-brown-50: #fbf3f0;
  --color-acoustic-brown-100: #efe6e2;
  --color-acoustic-brown-200: #ddd1cd;
  --color-acoustic-brown-300: #c2b4ae;
  --color-acoustic-brown-400: #ab9a94;
  --color-acoustic-brown-500: #94827b;
  --color-acoustic-brown-600: #7d6e68;
  --color-acoustic-brown-700: #645853;
  --color-acoustic-brown-800: #4a403d;
  --color-acoustic-brown-900: #332c2a;
  --color-acoustic-brown-950: #1f1917;
}

SCSS

$acoustic-brown: #81716b;
$acoustic-brown-rgb: 129, 113, 107;
$acoustic-brown-light: mix(#fff, $acoustic-brown, 20%);
$acoustic-brown-dark: mix(#000, $acoustic-brown, 20%);

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