#5F77A4

CSS

:root {
  --misty-harbour: #5f77a4;
  --misty-harbour-rgb: 95 119 164;
  --misty-harbour-oklch: oklch(0.569 0.076 262.6);
}

.element {
  color: var(--misty-harbour);
  background-color: hsl(219 27% 51%);
  border-color: oklch(0.569 0.076 262.6);
}

Tailwind CSS v4

@theme {
  --color-misty-harbour: #5f77a4;
  --color-misty-harbour-50: #eaf5ff;
  --color-misty-harbour-100: #dbe8ff;
  --color-misty-harbour-200: #c4d5f6;
  --color-misty-harbour-300: #a4b8df;
  --color-misty-harbour-400: #879fcc;
  --color-misty-harbour-500: #6b86b9;
  --color-misty-harbour-600: #5b729c;
  --color-misty-harbour-700: #485b7d;
  --color-misty-harbour-800: #33435d;
  --color-misty-harbour-900: #232e41;
  --color-misty-harbour-950: #121b2a;
}

SCSS

$misty-harbour: #5f77a4;
$misty-harbour-rgb: 95, 119, 164;
$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);
}