#316FAE

CSS

:root {
  --matt-blue: #316fae;
  --matt-blue-rgb: 49 111 174;
  --matt-blue-oklch: oklch(0.532 0.118 251.3);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(210 56% 44%);
  border-color: oklch(0.532 0.118 251.3);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #316fae;
  --color-matt-blue-50: #def8ff;
  --color-matt-blue-100: #cdebff;
  --color-matt-blue-200: #b1d8ff;
  --color-matt-blue-300: #8cbbf3;
  --color-matt-blue-400: #68a3e2;
  --color-matt-blue-500: #448ad1;
  --color-matt-blue-600: #3b75b1;
  --color-matt-blue-700: #2f5d8e;
  --color-matt-blue-800: #1e4569;
  --color-matt-blue-900: #14304a;
  --color-matt-blue-950: #051c31;
}

SCSS

$matt-blue: #316fae;
$matt-blue-rgb: 49, 111, 174;
$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);
}