#7B6867

CSS

:root {
  --acoustic-brown: #7b6867;
  --acoustic-brown-rgb: 123 104 103;
  --acoustic-brown-oklch: oklch(0.535 0.024 21.5);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(3 9% 44%);
  border-color: oklch(0.535 0.024 21.5);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #7b6867;
  --color-acoustic-brown-50: #fcf3f2;
  --color-acoustic-brown-100: #f0e5e4;
  --color-acoustic-brown-200: #dfd0cf;
  --color-acoustic-brown-300: #c4b3b1;
  --color-acoustic-brown-400: #ad9998;
  --color-acoustic-brown-500: #96807f;
  --color-acoustic-brown-600: #7f6d6c;
  --color-acoustic-brown-700: #655756;
  --color-acoustic-brown-800: #4b3f3f;
  --color-acoustic-brown-900: #342b2b;
  --color-acoustic-brown-950: #1f1919;
}

SCSS

$acoustic-brown: #7b6867;
$acoustic-brown-rgb: 123, 104, 103;
$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);
}