#756A64

CSS

:root {
  --acoustic-brown: #756a64;
  --acoustic-brown-rgb: 117 106 100;
  --acoustic-brown-oklch: oklch(0.533 0.017 50.6);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(21 8% 43%);
  border-color: oklch(0.533 0.017 50.6);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #756a64;
  --color-acoustic-brown-50: #f9f4f1;
  --color-acoustic-brown-100: #ede6e3;
  --color-acoustic-brown-200: #dad2ce;
  --color-acoustic-brown-300: #bfb5b0;
  --color-acoustic-brown-400: #a79c96;
  --color-acoustic-brown-500: #90837c;
  --color-acoustic-brown-600: #7a6f69;
  --color-acoustic-brown-700: #615954;
  --color-acoustic-brown-800: #47413d;
  --color-acoustic-brown-900: #322d2a;
  --color-acoustic-brown-950: #1d1a18;
}

SCSS

$acoustic-brown: #756a64;
$acoustic-brown-rgb: 117, 106, 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);
}