#736A6B

CSS

:root {
  --acoustic-brown: #736a6b;
  --acoustic-brown-rgb: 115 106 107;
  --acoustic-brown-oklch: oklch(0.533 0.011 9.8);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(353 4% 43%);
  border-color: oklch(0.533 0.011 9.8);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #736a6b;
  --color-acoustic-brown-50: #f8f4f4;
  --color-acoustic-brown-100: #ece6e7;
  --color-acoustic-brown-200: #d9d2d3;
  --color-acoustic-brown-300: #bdb5b6;
  --color-acoustic-brown-400: #a59c9d;
  --color-acoustic-brown-500: #8d8384;
  --color-acoustic-brown-600: #786f70;
  --color-acoustic-brown-700: #60595a;
  --color-acoustic-brown-800: #464142;
  --color-acoustic-brown-900: #312d2d;
  --color-acoustic-brown-950: #1d1a1a;
}

SCSS

$acoustic-brown: #736a6b;
$acoustic-brown-rgb: 115, 106, 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);
}