#437AAE

CSS

:root {
  --into-the-blue: #437aae;
  --into-the-blue-rgb: 67 122 174;
  --into-the-blue-oklch: oklch(0.565 0.1 248.8);
}

.element {
  color: var(--into-the-blue);
  background-color: hsl(209 44% 47%);
  border-color: oklch(0.565 0.1 248.8);
}

Tailwind CSS v4

@theme {
  --color-into-the-blue: #437aae;
  --color-into-the-blue-50: #e1f8ff;
  --color-into-the-blue-100: #d0ebff;
  --color-into-the-blue-200: #b5d8fe;
  --color-into-the-blue-300: #91bce9;
  --color-into-the-blue-400: #6ea3d7;
  --color-into-the-blue-500: #4d8bc5;
  --color-into-the-blue-600: #4276a7;
  --color-into-the-blue-700: #345e86;
  --color-into-the-blue-800: #234563;
  --color-into-the-blue-900: #173045;
  --color-into-the-blue-950: #081c2d;
}

SCSS

$into-the-blue: #437aae;
$into-the-blue-rgb: 67, 122, 174;
$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);
}