#00366A

CSS

:root {
  --lost-in-space: #00366a;
  --lost-in-space-rgb: 0 54 106;
  --lost-in-space-oklch: oklch(0.334 0.104 253.4);
}

.element {
  color: var(--lost-in-space);
  background-color: hsl(209 100% 21%);
  border-color: oklch(0.334 0.104 253.4);
}

Tailwind CSS v4

@theme {
  --color-lost-in-space: #00366a;
  --color-lost-in-space-50: #e2f7ff;
  --color-lost-in-space-100: #d1eaff;
  --color-lost-in-space-200: #b7d7ff;
  --color-lost-in-space-300: #94baed;
  --color-lost-in-space-400: #72a2db;
  --color-lost-in-space-500: #5289ca;
  --color-lost-in-space-600: #4674aa;
  --color-lost-in-space-700: #375d89;
  --color-lost-in-space-800: #254465;
  --color-lost-in-space-900: #192f47;
  --color-lost-in-space-950: #091b2e;
}

SCSS

$lost-in-space: #00366a;
$lost-in-space-rgb: 0, 54, 106;
$lost-in-space-light: mix(#fff, $lost-in-space, 20%);
$lost-in-space-dark: mix(#000, $lost-in-space, 20%);

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