#63779B

CSS

:root {
  --misty-harbour: #63779b;
  --misty-harbour-rgb: 99 119 155;
  --misty-harbour-oklch: oklch(0.567 0.061 262);
}

.element {
  color: var(--misty-harbour);
  background-color: hsl(219 22% 50%);
  border-color: oklch(0.567 0.061 262);
}

Tailwind CSS v4

@theme {
  --color-misty-harbour: #63779b;
  --color-misty-harbour-50: #ecf5ff;
  --color-misty-harbour-100: #dee8fd;
  --color-misty-harbour-200: #c7d5ef;
  --color-misty-harbour-300: #a8b8d7;
  --color-misty-harbour-400: #8b9fc3;
  --color-misty-harbour-500: #7087af;
  --color-misty-harbour-600: #5f7294;
  --color-misty-harbour-700: #4c5b77;
  --color-misty-harbour-800: #364358;
  --color-misty-harbour-900: #252e3d;
  --color-misty-harbour-950: #141b27;
}

SCSS

$misty-harbour: #63779b;
$misty-harbour-rgb: 99, 119, 155;
$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);
}