#004B63

CSS

:root {
  --raging-thunderstorm: #004b63;
  --raging-thunderstorm-rgb: 0 75 99;
  --raging-thunderstorm-oklch: oklch(0.385 0.075 227.8);
}

.element {
  color: var(--raging-thunderstorm);
  background-color: hsl(195 100% 19%);
  border-color: oklch(0.385 0.075 227.8);
}

Tailwind CSS v4

@theme {
  --color-raging-thunderstorm: #004b63;
  --color-raging-thunderstorm-50: #e0faff;
  --color-raging-thunderstorm-100: #cfedfc;
  --color-raging-thunderstorm-200: #b4dbee;
  --color-raging-thunderstorm-300: #90bfd7;
  --color-raging-thunderstorm-400: #6ea8c1;
  --color-raging-thunderstorm-500: #4b90ad;
  --color-raging-thunderstorm-600: #407a92;
  --color-raging-thunderstorm-700: #336275;
  --color-raging-thunderstorm-800: #234856;
  --color-raging-thunderstorm-900: #17323c;
  --color-raging-thunderstorm-950: #081e26;
}

SCSS

$raging-thunderstorm: #004b63;
$raging-thunderstorm-rgb: 0, 75, 99;
$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);
}