#226FB4

CSS

:root {
  --matt-blue: #226fb4;
  --matt-blue-rgb: 34 111 180;
  --matt-blue-oklch: oklch(0.531 0.131 250);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(208 68% 42%);
  border-color: oklch(0.531 0.131 250);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #226fb4;
  --color-matt-blue-50: #dbf8ff;
  --color-matt-blue-100: #c9ecff;
  --color-matt-blue-200: #acd9ff;
  --color-matt-blue-300: #85bcf9;
  --color-matt-blue-400: #5ea3e8;
  --color-matt-blue-500: #358ad9;
  --color-matt-blue-600: #2f75b7;
  --color-matt-blue-700: #255e93;
  --color-matt-blue-800: #16456d;
  --color-matt-blue-900: #0e304d;
  --color-matt-blue-950: #021c33;
}

SCSS

$matt-blue: #226fb4;
$matt-blue-rgb: 34, 111, 180;
$matt-blue-light: mix(#fff, $matt-blue, 20%);
$matt-blue-dark: mix(#000, $matt-blue, 20%);

.element {
  color: $matt-blue;
  box-shadow: 0 0 0 2px rgba($matt-blue, 0.35);
}