#246FB3

CSS

:root {
  --matt-blue: #246fb3;
  --matt-blue-rgb: 36 111 179;
  --matt-blue-oklch: oklch(0.531 0.129 250);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(209 67% 42%);
  border-color: oklch(0.531 0.129 250);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #246fb3;
  --color-matt-blue-50: #dbf8ff;
  --color-matt-blue-100: #c9ecff;
  --color-matt-blue-200: #add8ff;
  --color-matt-blue-300: #86bcf8;
  --color-matt-blue-400: #5fa3e7;
  --color-matt-blue-500: #378ad7;
  --color-matt-blue-600: #3075b6;
  --color-matt-blue-700: #265e92;
  --color-matt-blue-800: #17456c;
  --color-matt-blue-900: #0f304c;
  --color-matt-blue-950: #021c32;
}

SCSS

$matt-blue: #246fb3;
$matt-blue-rgb: 36, 111, 179;
$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);
}