#316DB7

CSS

:root {
  --matt-blue: #316db7;
  --matt-blue-rgb: 49 109 183;
  --matt-blue-oklch: oklch(0.533 0.132 255.2);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(213 58% 45%);
  border-color: oklch(0.533 0.132 255.2);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #316db7;
  --color-matt-blue-50: #def7ff;
  --color-matt-blue-100: #cceaff;
  --color-matt-blue-200: #b1d7ff;
  --color-matt-blue-300: #8cbafb;
  --color-matt-blue-400: #67a1eb;
  --color-matt-blue-500: #4487db;
  --color-matt-blue-600: #3a72b9;
  --color-matt-blue-700: #2e5c95;
  --color-matt-blue-800: #1d446f;
  --color-matt-blue-900: #132f4e;
  --color-matt-blue-950: #051b34;
}

SCSS

$matt-blue: #316db7;
$matt-blue-rgb: 49, 109, 183;
$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);
}