#627694

CSS

:root {
  --misty-harbour: #627694;
  --misty-harbour-rgb: 98 118 148;
  --misty-harbour-oklch: oklch(0.561 0.052 258.3);
}

.element {
  color: var(--misty-harbour);
  background-color: hsl(216 20% 48%);
  border-color: oklch(0.561 0.052 258.3);
}

Tailwind CSS v4

@theme {
  --color-misty-harbour: #627694;
  --color-misty-harbour-50: #edf6ff;
  --color-misty-harbour-100: #dee9fa;
  --color-misty-harbour-200: #c8d5eb;
  --color-misty-harbour-300: #a8b8d3;
  --color-misty-harbour-400: #8ca0be;
  --color-misty-harbour-500: #7187a9;
  --color-misty-harbour-600: #60738f;
  --color-misty-harbour-700: #4c5c73;
  --color-misty-harbour-800: #374355;
  --color-misty-harbour-900: #252e3b;
  --color-misty-harbour-950: #141b25;
}

SCSS

$misty-harbour: #627694;
$misty-harbour-rgb: 98, 118, 148;
$misty-harbour-light: mix(#fff, $misty-harbour, 20%);
$misty-harbour-dark: mix(#000, $misty-harbour, 20%);

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