#697491

CSS

:root {
  --misty-harbour: #697491;
  --misty-harbour-rgb: 105 116 145;
  --misty-harbour-oklch: oklch(0.561 0.047 268.6);
}

.element {
  color: var(--misty-harbour);
  background-color: hsl(224 16% 49%);
  border-color: oklch(0.561 0.047 268.6);
}

Tailwind CSS v4

@theme {
  --color-misty-harbour: #697491;
  --color-misty-harbour-50: #f0f5ff;
  --color-misty-harbour-100: #e2e7f8;
  --color-misty-harbour-200: #ccd4e9;
  --color-misty-harbour-300: #aeb7d0;
  --color-misty-harbour-400: #939ebb;
  --color-misty-harbour-500: #7985a6;
  --color-misty-harbour-600: #67718c;
  --color-misty-harbour-700: #525a71;
  --color-misty-harbour-800: #3b4253;
  --color-misty-harbour-900: #282e3a;
  --color-misty-harbour-950: #161a24;
}

SCSS

$misty-harbour: #697491;
$misty-harbour-rgb: 105, 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);
}