#6E4044

CSS

:root {
  --red-rumour: #6e4044;
  --red-rumour-rgb: 110 64 68;
  --red-rumour-oklch: oklch(0.428 0.064 14.5);
}

.element {
  color: var(--red-rumour);
  background-color: hsl(355 26% 34%);
  border-color: oklch(0.428 0.064 14.5);
}

Tailwind CSS v4

@theme {
  --color-red-rumour: #6e4044;
  --color-red-rumour-50: #ffeeef;
  --color-red-rumour-100: #fde0e0;
  --color-red-rumour-200: #efcacb;
  --color-red-rumour-300: #d6abac;
  --color-red-rumour-400: #c18f92;
  --color-red-rumour-500: #ad7579;
  --color-red-rumour-600: #926366;
  --color-red-rumour-700: #754f52;
  --color-red-rumour-800: #56393c;
  --color-red-rumour-900: #3c2729;
  --color-red-rumour-950: #261517;
}

SCSS

$red-rumour: #6e4044;
$red-rumour-rgb: 110, 64, 68;
$red-rumour-light: mix(#fff, $red-rumour, 20%);
$red-rumour-dark: mix(#000, $red-rumour, 20%);

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