#0D0E49

CSS

:root {
  --storm: #0d0e49;
  --storm-rgb: 13 14 73;
  --storm-oklch: oklch(0.216 0.106 272.5);
}

.element {
  color: var(--storm);
  background-color: hsl(239 70% 17%);
  border-color: oklch(0.216 0.106 272.5);
}

Tailwind CSS v4

@theme {
  --color-storm: #0d0e49;
  --color-storm-50: #ecf4ff;
  --color-storm-100: #dde6ff;
  --color-storm-200: #c6d2ff;
  --color-storm-300: #a7b4ee;
  --color-storm-400: #899add;
  --color-storm-500: #6f80cc;
  --color-storm-600: #5e6dac;
  --color-storm-700: #4b578a;
  --color-storm-800: #354067;
  --color-storm-900: #242c48;
  --color-storm-950: #13192f;
}

SCSS

$storm: #0d0e49;
$storm-rgb: 13, 14, 73;
$storm-light: mix(#fff, $storm, 20%);
$storm-dark: mix(#000, $storm, 20%);

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