#78686A

CSS

:root {
  --acoustic-brown: #78686a;
  --acoustic-brown-rgb: 120 104 106;
  --acoustic-brown-oklch: oklch(0.533 0.021 9.3);
}

.element {
  color: var(--acoustic-brown);
  background-color: hsl(353 7% 44%);
  border-color: oklch(0.533 0.021 9.3);
}

Tailwind CSS v4

@theme {
  --color-acoustic-brown: #78686a;
  --color-acoustic-brown-50: #fbf3f3;
  --color-acoustic-brown-100: #efe5e6;
  --color-acoustic-brown-200: #ddd1d2;
  --color-acoustic-brown-300: #c2b3b5;
  --color-acoustic-brown-400: #aa9a9c;
  --color-acoustic-brown-500: #938183;
  --color-acoustic-brown-600: #7c6d6f;
  --color-acoustic-brown-700: #645759;
  --color-acoustic-brown-800: #494041;
  --color-acoustic-brown-900: #332c2d;
  --color-acoustic-brown-950: #1e191a;
}

SCSS

$acoustic-brown: #78686a;
$acoustic-brown-rgb: 120, 104, 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);
}