Old Glory Blue

CSS

:root {
  --old-glory-blue: #002868;
  --old-glory-blue-rgb: 0 40 104;
  --old-glory-blue-oklch: oklch(0.299 0.12 259.8);
}

.element {
  color: var(--old-glory-blue);
  background-color: hsl(217 100% 20%);
  border-color: oklch(0.299 0.12 259.8);
}

Tailwind CSS v4

@theme {
  --color-old-glory-blue: #002868;
  --color-old-glory-blue-50: #e3f6ff;
  --color-old-glory-blue-100: #d2e9ff;
  --color-old-glory-blue-200: #b8d5ff;
  --color-old-glory-blue-300: #95b8f6;
  --color-old-glory-blue-400: #749fe5;
  --color-old-glory-blue-500: #5585d5;
  --color-old-glory-blue-600: #4871b4;
  --color-old-glory-blue-700: #395a90;
  --color-old-glory-blue-800: #26436b;
  --color-old-glory-blue-900: #1a2e4c;
  --color-old-glory-blue-950: #0a1a32;
}

SCSS

$old-glory-blue: #002868;
$old-glory-blue-rgb: 0, 40, 104;
$old-glory-blue-light: mix(#fff, $old-glory-blue, 20%);
$old-glory-blue-dark: mix(#000, $old-glory-blue, 20%);

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