#2B70A8

CSS

:root {
  --muted-blue: #2b70a8;
  --muted-blue-rgb: 43 112 168;
  --muted-blue-oklch: oklch(0.529 0.112 246.7);
}

.element {
  color: var(--muted-blue);
  background-color: hsl(207 59% 41%);
  border-color: oklch(0.529 0.112 246.7);
}

Tailwind CSS v4

@theme {
  --color-muted-blue: #2b70a8;
  --color-muted-blue-50: #ddf9ff;
  --color-muted-blue-100: #ccecff;
  --color-muted-blue-200: #afd9ff;
  --color-muted-blue-300: #8abdee;
  --color-muted-blue-400: #65a4dd;
  --color-muted-blue-500: #3f8ccc;
  --color-muted-blue-600: #3776ac;
  --color-muted-blue-700: #2b5f8a;
  --color-muted-blue-800: #1c4666;
  --color-muted-blue-900: #123048;
  --color-muted-blue-950: #041c2f;
}

SCSS

$muted-blue: #2b70a8;
$muted-blue-rgb: 43, 112, 168;
$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);
}