#6A3231

CSS

:root {
  --arcane-red: #6a3231;
  --arcane-red-rgb: 106 50 49;
  --arcane-red-oklch: oklch(0.391 0.08 22.5);
}

.element {
  color: var(--arcane-red);
  background-color: hsl(1 37% 30%);
  border-color: oklch(0.391 0.08 22.5);
}

Tailwind CSS v4

@theme {
  --color-arcane-red: #6a3231;
  --color-arcane-red-50: #ffedea;
  --color-arcane-red-100: #ffdedb;
  --color-arcane-red-200: #f5c8c3;
  --color-arcane-red-300: #dea8a3;
  --color-arcane-red-400: #ca8c89;
  --color-arcane-red-500: #b6706d;
  --color-arcane-red-600: #995f5d;
  --color-arcane-red-700: #7b4c4a;
  --color-arcane-red-800: #5b3736;
  --color-arcane-red-900: #402625;
  --color-arcane-red-950: #291414;
}

SCSS

$arcane-red: #6a3231;
$arcane-red-rgb: 106, 50, 49;
$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);
}