#6B7491

CSS

:root {
  --misty-harbour: #6b7491;
  --misty-harbour-rgb: 107 116 145;
  --misty-harbour-oklch: oklch(0.562 0.046 271.4);
}

.element {
  color: var(--misty-harbour);
  background-color: hsl(226 15% 49%);
  border-color: oklch(0.562 0.046 271.4);
}

Tailwind CSS v4

@theme {
  --color-misty-harbour: #6b7491;
  --color-misty-harbour-50: #f1f5ff;
  --color-misty-harbour-100: #e3e7f8;
  --color-misty-harbour-200: #cdd3e9;
  --color-misty-harbour-300: #afb6d0;
  --color-misty-harbour-400: #949dbb;
  --color-misty-harbour-500: #7b85a6;
  --color-misty-harbour-600: #68718c;
  --color-misty-harbour-700: #535a70;
  --color-misty-harbour-800: #3c4253;
  --color-misty-harbour-900: #292d3a;
  --color-misty-harbour-950: #171a24;
}

SCSS

$misty-harbour: #6b7491;
$misty-harbour-rgb: 107, 116, 145;
$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);
}