#646DC2

CSS

:root {
  --loch-ness: #646dc2;
  --loch-ness-rgb: 100 109 194;
  --loch-ness-oklch: oklch(0.567 0.13 276.8);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(234 44% 58%);
  border-color: oklch(0.567 0.13 276.8);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #646dc2;
  --color-loch-ness-50: #ecf2ff;
  --color-loch-ness-100: #dee4ff;
  --color-loch-ness-200: #c7cfff;
  --color-loch-ness-300: #a9b1fa;
  --color-loch-ness-400: #8b96eb;
  --color-loch-ness-500: #717bdb;
  --color-loch-ness-600: #6069b9;
  --color-loch-ness-700: #4d5494;
  --color-loch-ness-800: #363d6f;
  --color-loch-ness-900: #242a4e;
  --color-loch-ness-950: #131734;
}

SCSS

$loch-ness: #646dc2;
$loch-ness-rgb: 100, 109, 194;
$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);
}