#5279A3

CSS

:root {
  --into-the-blue: #5279a3;
  --into-the-blue-rgb: 82 121 163;
  --into-the-blue-oklch: oklch(0.565 0.079 251.1);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(211 33% 48%);
  border-color: oklch(0.565 0.079 251.1);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #5279a3;
  --color-into-the-blue-50: #e6f7ff;
  --color-into-the-blue-100: #d6eaff;
  --color-into-the-blue-200: #bdd7f6;
  --color-into-the-blue-300: #9bbae0;
  --color-into-the-blue-400: #7ca2cc;
  --color-into-the-blue-500: #5e8ab9;
  --color-into-the-blue-600: #50759c;
  --color-into-the-blue-700: #405d7d;
  --color-into-the-blue-800: #2c455d;
  --color-into-the-blue-900: #1e2f41;
  --color-into-the-blue-950: #0e1c2a;
}

SCSS

$into-the-blue: #5279a3;
$into-the-blue-rgb: 82, 121, 163;
$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);
}