#6A3534

CSS

:root {
  --arcane-red: #6a3534;
  --arcane-red-rgb: 106 53 52;
  --arcane-red-oklch: oklch(0.397 0.076 22.2);
}

.element {
  color: var(--arcane-red);
  background-color: hsl(1 34% 31%);
  border-color: oklch(0.397 0.076 22.2);
}

Tailwind CSS v4

@theme {
  --color-arcane-red: #6a3534;
  --color-arcane-red-50: #ffedeb;
  --color-arcane-red-100: #ffdfdc;
  --color-arcane-red-200: #f3c8c4;
  --color-arcane-red-300: #dca9a4;
  --color-arcane-red-400: #c88d8a;
  --color-arcane-red-500: #b3726f;
  --color-arcane-red-600: #97615e;
  --color-arcane-red-700: #794d4b;
  --color-arcane-red-800: #5a3837;
  --color-arcane-red-900: #3f2626;
  --color-arcane-red-950: #281414;
}

SCSS

$arcane-red: #6a3534;
$arcane-red-rgb: 106, 53, 52;
$arcane-red-light: mix(#fff, $arcane-red, 20%);
$arcane-red-dark: mix(#000, $arcane-red, 20%);

.element {
  color: $arcane-red;
  box-shadow: 0 0 0 2px rgba($arcane-red, 0.35);
}