#005164

CSS

:root {
  --raging-thunderstorm: #005164;
  --raging-thunderstorm-rgb: 0 81 100;
  --raging-thunderstorm-oklch: oklch(0.403 0.074 220.6);
}

.element {
  color: var(--raging-thunderstorm);
  background-color: hsl(191 100% 20%);
  border-color: oklch(0.403 0.074 220.6);
}

Tailwind CSS v4

@theme {
  --color-raging-thunderstorm: #005164;
  --color-raging-thunderstorm-50: #dffaff;
  --color-raging-thunderstorm-100: #ceeefa;
  --color-raging-thunderstorm-200: #b3dceb;
  --color-raging-thunderstorm-300: #8ec0d3;
  --color-raging-thunderstorm-400: #6ba9bd;
  --color-raging-thunderstorm-500: #4791a8;
  --color-raging-thunderstorm-600: #3e7b8e;
  --color-raging-thunderstorm-700: #316372;
  --color-raging-thunderstorm-800: #214954;
  --color-raging-thunderstorm-900: #16323a;
  --color-raging-thunderstorm-950: #071e24;
}

SCSS

$raging-thunderstorm: #005164;
$raging-thunderstorm-rgb: 0, 81, 100;
$raging-thunderstorm-light: mix(#fff, $raging-thunderstorm, 20%);
$raging-thunderstorm-dark: mix(#000, $raging-thunderstorm, 20%);

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