#4879A4

CSS

:root {
  --into-the-blue: #4879a4;
  --into-the-blue-rgb: 72 121 164;
  --into-the-blue-oklch: oklch(0.56 0.086 246.5);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(208 39% 46%);
  border-color: oklch(0.56 0.086 246.5);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #4879a4;
  --color-into-the-blue-50: #e3f8ff;
  --color-into-the-blue-100: #d2ebff;
  --color-into-the-blue-200: #b8d8f8;
  --color-into-the-blue-300: #95bce2;
  --color-into-the-blue-400: #74a4cf;
  --color-into-the-blue-500: #548bbc;
  --color-into-the-blue-600: #48769f;
  --color-into-the-blue-700: #395e7f;
  --color-into-the-blue-800: #27455e;
  --color-into-the-blue-900: #1a3042;
  --color-into-the-blue-950: #0a1c2a;
}

SCSS

$into-the-blue: #4879a4;
$into-the-blue-rgb: 72, 121, 164;
$into-the-blue-light: mix(#fff, $into-the-blue, 20%);
$into-the-blue-dark: mix(#000, $into-the-blue, 20%);

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