#3271A2

CSS

:root {
  --muted-blue: #3271a2;
  --muted-blue-rgb: 50 113 162;
  --muted-blue-oklch: oklch(0.53 0.101 244.9);
}

.element {
  color: var(--muted-blue);
  background-color: hsl(206 53% 42%);
  border-color: oklch(0.53 0.101 244.9);
}

Tailwind CSS v4

@theme {
  --color-muted-blue: #3271a2;
  --color-muted-blue-50: #dff9ff;
  --color-muted-blue-100: #ceecff;
  --color-muted-blue-200: #b2d9fe;
  --color-muted-blue-300: #8dbde9;
  --color-muted-blue-400: #69a5d6;
  --color-muted-blue-500: #468cc4;
  --color-muted-blue-600: #3c77a6;
  --color-muted-blue-700: #305f85;
  --color-muted-blue-800: #1f4662;
  --color-muted-blue-900: #153045;
  --color-muted-blue-950: #061d2d;
}

SCSS

$muted-blue: #3271a2;
$muted-blue-rgb: 50, 113, 162;
$muted-blue-light: mix(#fff, $muted-blue, 20%);
$muted-blue-dark: mix(#000, $muted-blue, 20%);

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