#7C6767

CSS

:root {
  --acoustic-brown: #7c6767;
  --acoustic-brown-rgb: 124 103 103;
  --acoustic-brown-oklch: oklch(0.534 0.027 18);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(0 9% 45%);
  border-color: oklch(0.534 0.027 18);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #7c6767;
  --color-acoustic-brown-50: #fdf2f2;
  --color-acoustic-brown-100: #f1e4e4;
  --color-acoustic-brown-200: #e0d0cf;
  --color-acoustic-brown-300: #c5b2b2;
  --color-acoustic-brown-400: #ae9898;
  --color-acoustic-brown-500: #977f7f;
  --color-acoustic-brown-600: #806c6c;
  --color-acoustic-brown-700: #675656;
  --color-acoustic-brown-800: #4b3f3f;
  --color-acoustic-brown-900: #342b2b;
  --color-acoustic-brown-950: #201919;
}

SCSS

$acoustic-brown: #7c6767;
$acoustic-brown-rgb: 124, 103, 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);
}