#C65315

CSS

:root {
  --dark-orange: #c65315;
  --dark-orange-rgb: 198 83 21;
  --dark-orange-oklch: oklch(0.583 0.162 43.6);
}

.element {
  color: var(--dark-orange);
  background-color: hsl(21 81% 43%);
  border-color: oklch(0.583 0.162 43.6);
}

Tailwind CSS v4

@theme {
  --color-dark-orange: #c65315;
  --color-dark-orange-50: #ffe8cf;
  --color-dark-orange-100: #ffd8bb;
  --color-dark-orange-200: #ffbf9a;
  --color-dark-orange-300: #fb9c6f;
  --color-dark-orange-400: #eb7a48;
  --color-dark-orange-500: #d9580b;
  --color-dark-orange-600: #b74c11;
  --color-dark-orange-700: #933c0e;
  --color-dark-orange-800: #6e2a0b;
  --color-dark-orange-900: #4e1d07;
  --color-dark-orange-950: #330c00;
}

SCSS

$dark-orange: #c65315;
$dark-orange-rgb: 198, 83, 21;
$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);
}