#4D78A2

CSS

:root {
  --into-the-blue: #4d78a2;
  --into-the-blue-rgb: 77 120 162;
  --into-the-blue-oklch: oklch(0.559 0.081 248.9);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(210 36% 47%);
  border-color: oklch(0.559 0.081 248.9);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #4d78a2;
  --color-into-the-blue-50: #e5f7ff;
  --color-into-the-blue-100: #d5ebff;
  --color-into-the-blue-200: #bbd7f7;
  --color-into-the-blue-300: #99bbe0;
  --color-into-the-blue-400: #79a3cd;
  --color-into-the-blue-500: #5a8aba;
  --color-into-the-blue-600: #4d759d;
  --color-into-the-blue-700: #3d5e7e;
  --color-into-the-blue-800: #2a455d;
  --color-into-the-blue-900: #1c3041;
  --color-into-the-blue-950: #0c1c2a;
}

SCSS

$into-the-blue: #4d78a2;
$into-the-blue-rgb: 77, 120, 162;
$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);
}