#5F71B7

CSS

:root {
  --loch-ness: #5f71b7;
  --loch-ness-rgb: 95 113 183;
  --loch-ness-oklch: oklch(0.566 0.111 271.6);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(228 38% 55%);
  border-color: oklch(0.566 0.111 271.6);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #5f71b7;
  --color-loch-ness-50: #ebf4ff;
  --color-loch-ness-100: #dce6ff;
  --color-loch-ness-200: #c5d2ff;
  --color-loch-ness-300: #a5b4f1;
  --color-loch-ness-400: #879ae0;
  --color-loch-ness-500: #6c80cf;
  --color-loch-ness-600: #5c6daf;
  --color-loch-ness-700: #49578c;
  --color-loch-ness-800: #334069;
  --color-loch-ness-900: #232c4a;
  --color-loch-ness-950: #121930;
}

SCSS

$loch-ness: #5f71b7;
$loch-ness-rgb: 95, 113, 183;
$loch-ness-light: mix(#fff, $loch-ness, 20%);
$loch-ness-dark: mix(#000, $loch-ness, 20%);

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