#003965

CSS

:root {
  --lost-in-space: #003965;
  --lost-in-space-rgb: 0 57 101;
  --lost-in-space-oklch: oklch(0.338 0.094 249.1);
}

.element {
  color: var(--lost-in-space);
  background-color: hsl(206 100% 20%);
  border-color: oklch(0.338 0.094 249.1);
}

Tailwind CSS v4

@theme {
  --color-lost-in-space: #003965;
  --color-lost-in-space-50: #e2f8ff;
  --color-lost-in-space-100: #d2ebff;
  --color-lost-in-space-200: #b7d8fc;
  --color-lost-in-space-300: #94bbe6;
  --color-lost-in-space-400: #72a3d4;
  --color-lost-in-space-500: #528bc1;
  --color-lost-in-space-600: #4675a3;
  --color-lost-in-space-700: #385e83;
  --color-lost-in-space-800: #264561;
  --color-lost-in-space-900: #193044;
  --color-lost-in-space-950: #0a1c2c;
}

SCSS

$lost-in-space: #003965;
$lost-in-space-rgb: 0, 57, 101;
$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);
}