#7D1103

CSS

:root {
  --indian-red: #7d1103;
  --indian-red-rgb: 125 17 3;
  --indian-red-oklch: oklch(0.38 0.143 31.2);
}

.element {
  color: var(--indian-red);
  background-color: hsl(7 95% 25%);
  border-color: oklch(0.38 0.143 31.2);
}

Tailwind CSS v4

@theme {
  --color-indian-red: #7d1103;
  --color-indian-red-50: #ffe7db;
  --color-indian-red-100: #ffd7c9;
  --color-indian-red-200: #ffbead;
  --color-indian-red-300: #f79c87;
  --color-indian-red-400: #e67b68;
  --color-indian-red-500: #d45a47;
  --color-indian-red-600: #b34d3d;
  --color-indian-red-700: #903e30;
  --color-indian-red-800: #6b2c24;
  --color-indian-red-900: #4c1d18;
  --color-indian-red-950: #320d09;
}

SCSS

$indian-red: #7d1103;
$indian-red-rgb: 125, 17, 3;
$indian-red-light: mix(#fff, $indian-red, 20%);
$indian-red-dark: mix(#000, $indian-red, 20%);

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