#0B4B5F

CSS

:root {
  --raging-thunderstorm: #0b4b5f;
  --raging-thunderstorm-rgb: 11 75 95;
  --raging-thunderstorm-oklch: oklch(0.385 0.068 224.9);
}

.element {
  color: var(--raging-thunderstorm);
  background-color: hsl(194 79% 21%);
  border-color: oklch(0.385 0.068 224.9);
}

Tailwind CSS v4

@theme {
  --color-raging-thunderstorm: #0b4b5f;
  --color-raging-thunderstorm-50: #e2faff;
  --color-raging-thunderstorm-100: #d1edfa;
  --color-raging-thunderstorm-200: #b7dbeb;
  --color-raging-thunderstorm-300: #93bfd3;
  --color-raging-thunderstorm-400: #72a7bd;
  --color-raging-thunderstorm-500: #5090a8;
  --color-raging-thunderstorm-600: #457a8e;
  --color-raging-thunderstorm-700: #376172;
  --color-raging-thunderstorm-800: #264854;
  --color-raging-thunderstorm-900: #19323a;
  --color-raging-thunderstorm-950: #0a1e24;
}

SCSS

$raging-thunderstorm: #0b4b5f;
$raging-thunderstorm-rgb: 11, 75, 95;
$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);
}