#4E79AC

CSS

:root {
  --into-the-blue: #4e79ac;
  --into-the-blue-rgb: 78 121 172;
  --into-the-blue-oklch: oklch(0.567 0.093 253.5);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(213 38% 49%);
  border-color: oklch(0.567 0.093 253.5);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #4e79ac;
  --color-into-the-blue-50: #e4f7ff;
  --color-into-the-blue-100: #d4eaff;
  --color-into-the-blue-200: #bad7fc;
  --color-into-the-blue-300: #98bae7;
  --color-into-the-blue-400: #77a2d4;
  --color-into-the-blue-500: #5989c2;
  --color-into-the-blue-600: #4b74a4;
  --color-into-the-blue-700: #3c5d84;
  --color-into-the-blue-800: #294462;
  --color-into-the-blue-900: #1c2f44;
  --color-into-the-blue-950: #0c1c2c;
}

SCSS

$into-the-blue: #4e79ac;
$into-the-blue-rgb: 78, 121, 172;
$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);
}