#666FB5

CSS

:root {
  --loch-ness: #666fb5;
  --loch-ness-rgb: 102 111 181;
  --loch-ness-oklch: oklch(0.565 0.108 276.8);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(233 35% 55%);
  border-color: oklch(0.565 0.108 276.8);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #666fb5;
  --color-loch-ness-50: #eef3ff;
  --color-loch-ness-100: #dfe5ff;
  --color-loch-ness-200: #c9d0ff;
  --color-loch-ness-300: #abb2ef;
  --color-loch-ness-400: #8e98de;
  --color-loch-ness-500: #747ecd;
  --color-loch-ness-600: #626bad;
  --color-loch-ness-700: #4e568b;
  --color-loch-ness-800: #373f68;
  --color-loch-ness-900: #262b49;
  --color-loch-ness-950: #141830;
}

SCSS

$loch-ness: #666fb5;
$loch-ness-rgb: 102, 111, 181;
$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);
}