#776964

CSS

:root {
  --acoustic-brown: #776964;
  --acoustic-brown-rgb: 119 105 100;
  --acoustic-brown-oklch: oklch(0.532 0.019 40.7);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(16 9% 43%);
  border-color: oklch(0.532 0.019 40.7);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #776964;
  --color-acoustic-brown-50: #faf3f1;
  --color-acoustic-brown-100: #eee6e3;
  --color-acoustic-brown-200: #dcd2ce;
  --color-acoustic-brown-300: #c1b4b0;
  --color-acoustic-brown-400: #a99b96;
  --color-acoustic-brown-500: #92827c;
  --color-acoustic-brown-600: #7c6e69;
  --color-acoustic-brown-700: #635854;
  --color-acoustic-brown-800: #49403d;
  --color-acoustic-brown-900: #322c2a;
  --color-acoustic-brown-950: #1e1918;
}

SCSS

$acoustic-brown: #776964;
$acoustic-brown-rgb: 119, 105, 100;
$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);
}