#C64F0F

CSS

:root {
  --dark-orange: #c64f0f;
  --dark-orange-rgb: 198 79 15;
  --dark-orange-oklch: oklch(0.578 0.166 42.7);
}

.element {
  color: var(--dark-orange);
  background-color: hsl(21 86% 42%);
  border-color: oklch(0.578 0.166 42.7);
}

Tailwind CSS v4

@theme {
  --color-dark-orange: #c64f0f;
  --color-dark-orange-50: #ffe7cf;
  --color-dark-orange-100: #ffd7bb;
  --color-dark-orange-200: #ffbe99;
  --color-dark-orange-300: #fd9a6e;
  --color-dark-orange-400: #ed7947;
  --color-dark-orange-500: #db5606;
  --color-dark-orange-600: #b94a0e;
  --color-dark-orange-700: #953b0c;
  --color-dark-orange-800: #6f290b;
  --color-dark-orange-900: #4f1c07;
  --color-dark-orange-950: #340b00;
}

SCSS

$dark-orange: #c64f0f;
$dark-orange-rgb: 198, 79, 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);
}