#81716D

CSS

:root {
  --acoustic-brown: #81716d;
  --acoustic-brown-rgb: 129 113 109;
  --acoustic-brown-oklch: oklch(0.562 0.021 34.3);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(12 8% 47%);
  border-color: oklch(0.562 0.021 34.3);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #81716d;
  --color-acoustic-brown-50: #fbf3f1;
  --color-acoustic-brown-100: #efe6e3;
  --color-acoustic-brown-200: #ddd1ce;
  --color-acoustic-brown-300: #c2b4b0;
  --color-acoustic-brown-400: #aa9a96;
  --color-acoustic-brown-500: #94827d;
  --color-acoustic-brown-600: #7d6e6a;
  --color-acoustic-brown-700: #645855;
  --color-acoustic-brown-800: #49403e;
  --color-acoustic-brown-900: #332c2a;
  --color-acoustic-brown-950: #1f1918;
}

SCSS

$acoustic-brown: #81716d;
$acoustic-brown-rgb: 129, 113, 109;
$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);
}