#4B79AB

CSS

:root {
  --into-the-blue: #4b79ab;
  --into-the-blue-rgb: 75 121 171;
  --into-the-blue-oklch: oklch(0.565 0.093 251.6);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(211 39% 48%);
  border-color: oklch(0.565 0.093 251.6);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #4b79ab;
  --color-into-the-blue-50: #e3f7ff;
  --color-into-the-blue-100: #d3eaff;
  --color-into-the-blue-200: #b9d7fc;
  --color-into-the-blue-300: #96bbe7;
  --color-into-the-blue-400: #75a2d4;
  --color-into-the-blue-500: #568ac2;
  --color-into-the-blue-600: #4975a4;
  --color-into-the-blue-700: #3a5d83;
  --color-into-the-blue-800: #284561;
  --color-into-the-blue-900: #1b2f44;
  --color-into-the-blue-950: #0b1c2c;
}

SCSS

$into-the-blue: #4b79ab;
$into-the-blue-rgb: 75, 121, 171;
$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);
}