#736A6A

CSS

:root {
  --acoustic-brown: #736a6a;
  --acoustic-brown-rgb: 115 106 106;
  --acoustic-brown-oklch: oklch(0.533 0.011 17.5);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(0 4% 43%);
  border-color: oklch(0.533 0.011 17.5);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #736a6a;
  --color-acoustic-brown-50: #f8f4f4;
  --color-acoustic-brown-100: #ece6e6;
  --color-acoustic-brown-200: #d9d2d2;
  --color-acoustic-brown-300: #bdb5b5;
  --color-acoustic-brown-400: #a59c9c;
  --color-acoustic-brown-500: #8e8383;
  --color-acoustic-brown-600: #786f6f;
  --color-acoustic-brown-700: #605959;
  --color-acoustic-brown-800: #464141;
  --color-acoustic-brown-900: #312d2d;
  --color-acoustic-brown-950: #1d1a1a;
}

SCSS

$acoustic-brown: #736a6a;
$acoustic-brown-rgb: 115, 106, 106;
$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);
}