#011248

CSS

:root {
  --storm: #011248;
  --storm-rgb: 1 18 72;
  --storm-oklch: oklch(0.216 0.103 263.2);
}

.element {
  color: var(--storm);
  background-color: hsl(226 97% 14%);
  border-color: oklch(0.216 0.103 263.2);
}

Tailwind CSS v4

@theme {
  --color-storm: #011248;
  --color-storm-50: #e7f5ff;
  --color-storm-100: #d7e8ff;
  --color-storm-200: #bfd4ff;
  --color-storm-300: #9eb7ed;
  --color-storm-400: #7e9edc;
  --color-storm-500: #6285cb;
  --color-storm-600: #5370ab;
  --color-storm-700: #425a89;
  --color-storm-800: #2e4266;
  --color-storm-900: #1f2e48;
  --color-storm-950: #0f1a2f;
}

SCSS

$storm: #011248;
$storm-rgb: 1, 18, 72;
$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);
}