#686FB5

CSS

:root {
  --loch-ness: #686fb5;
  --loch-ness-rgb: 104 111 181;
  --loch-ness-oklch: oklch(0.567 0.108 278);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(235 34% 56%);
  border-color: oklch(0.567 0.108 278);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #686fb5;
  --color-loch-ness-50: #eef3ff;
  --color-loch-ness-100: #e0e5ff;
  --color-loch-ness-200: #cad0ff;
  --color-loch-ness-300: #acb2ee;
  --color-loch-ness-400: #8f98de;
  --color-loch-ness-500: #767ecd;
  --color-loch-ness-600: #646bad;
  --color-loch-ness-700: #50558b;
  --color-loch-ness-800: #383f67;
  --color-loch-ness-900: #272b49;
  --color-loch-ness-950: #151830;
}

SCSS

$loch-ness: #686fb5;
$loch-ness-rgb: 104, 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);
}