#C5540F

CSS

:root {
  --dark-orange: #c5540f;
  --dark-orange-rgb: 197 84 15;
  --dark-orange-oklch: oklch(0.583 0.161 45);
}

.element {
  color: var(--dark-orange);
  background-color: hsl(23 86% 42%);
  border-color: oklch(0.583 0.161 45);
}

Tailwind CSS v4

@theme {
  --color-dark-orange: #c5540f;
  --color-dark-orange-50: #ffe8ce;
  --color-dark-orange-100: #ffd8ba;
  --color-dark-orange-200: #ffbf99;
  --color-dark-orange-300: #fa9c6d;
  --color-dark-orange-400: #ea7b46;
  --color-dark-orange-500: #d85a01;
  --color-dark-orange-600: #b74d0b;
  --color-dark-orange-700: #933d0a;
  --color-dark-orange-800: #6e2b09;
  --color-dark-orange-900: #4d1d06;
  --color-dark-orange-950: #330c00;
}

SCSS

$dark-orange: #c5540f;
$dark-orange-rgb: 197, 84, 15;
$dark-orange-light: mix(#fff, $dark-orange, 20%);
$dark-orange-dark: mix(#000, $dark-orange, 20%);

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