#6370B7

CSS

:root {
  --loch-ness: #6370b7;
  --loch-ness-rgb: 99 112 183;
  --loch-ness-oklch: oklch(0.566 0.111 274.5);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(231 37% 55%);
  border-color: oklch(0.566 0.111 274.5);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #6370b7;
  --color-loch-ness-50: #ecf3ff;
  --color-loch-ness-100: #dee5ff;
  --color-loch-ness-200: #c7d1ff;
  --color-loch-ness-300: #a8b3f0;
  --color-loch-ness-400: #8b99e0;
  --color-loch-ness-500: #707fcf;
  --color-loch-ness-600: #5f6caf;
  --color-loch-ness-700: #4c568c;
  --color-loch-ness-800: #353f69;
  --color-loch-ness-900: #242c4a;
  --color-loch-ness-950: #131930;
}

SCSS

$loch-ness: #6370b7;
$loch-ness-rgb: 99, 112, 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);
}