#0A0E4B

CSS

:root {
  --storm: #0a0e4b;
  --storm-rgb: 10 14 75;
  --storm-oklch: oklch(0.217 0.109 270.2);
}

.element {
  color: var(--storm);
  background-color: hsl(236 76% 17%);
  border-color: oklch(0.217 0.109 270.2);
}

Tailwind CSS v4

@theme {
  --color-storm: #0a0e4b;
  --color-storm-50: #eaf4ff;
  --color-storm-100: #dbe6ff;
  --color-storm-200: #c4d2ff;
  --color-storm-300: #a4b4f0;
  --color-storm-400: #859bdf;
  --color-storm-500: #6a81cf;
  --color-storm-600: #5a6dae;
  --color-storm-700: #48588c;
  --color-storm-800: #324068;
  --color-storm-900: #222c49;
  --color-storm-950: #111930;
}

SCSS

$storm: #0a0e4b;
$storm-rgb: 10, 14, 75;
$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);
}